@@jameslewis7620 Most computer companies did for monitors. CRT construction is far enough removed from everything else involved in making a computer that even highly-integrated companies tended to pay a TV company to make them a display.
According to the "Phosphor Handbook", P39 and P42 are both "yellowish-green" in color. The P-numbers are the EIA designation for the different phosphor types.
@Adrian's Digital Basement .. if you want to put a "new" anti glare filter at 13:50 ... you know for historical proposites or something like that.. you can get one from this vintage Anti-glare fiber "fultra fine nylon mesh" (image 4) »» www.ebay.com/itm/Vintage-Computer-CRT-Screen-Anti-glare-Color-Monitor-Filter-1988-MAC-IBM-NEC-/174168256917
When I was a kid my friend had a Monitor /// for his Apple IIE, and I fell in love with the color of that green monochrome tube. I only had a b/w television to use as a monitor for my Atari 400, and by comparison the Apple's green was way, way sexier (a little bit ironic too, as my Atari actually had the better color and grayscale capability). I liked the green Apple display aesthetic so much that I used to POKE my school's C64s to green text on a borderless black background every time I powered mine on. To me nothing recalls the feeling of early home computing more than a monochrome display.
Had a "lemon" of a hdd from hitachi (came in a toshiba laptop) once, several diagnostics told me it was faulted and would soon die. I was still running that faulted drive about 6, 7 years later. It hadn't gotten any worse, still worked fine, read wrote, and absolutely never crashed. Every review of that drive i found said it was unreliable. I found that not to be the case. I just finally retired it about 2 weeks ago, as i had built an lfs system on it and want to rescue it off of it before it does actually stop working. Do indeed respect hitachi, even the lemons never die.
I bought 4 30GB Deskstars about 17 years ago. I had them in RAID5 so if something happened I could recover stuff. Just retired them almost a year ago (they were holding unimportant stuff lately) still going strong... I think it was only a certain drive from the IBM days that had problems, but it tarnished the name forever.
16:00 re: going backwards before forwards when screwing in. I've always done that since I was a little kid. Just seemed to make sense that I didn't want to wreck the threads. (Before I figured that out I definitely stripped some screws.)
@@jason50146 in one of the videos on my channel I found an old HP, and inside were a few expansion cards. Now, instead of taking their time, the previous owner had strong-armed new threads into the post at a 45 degree angle rather than bother to seat the card properly. Sadly, that was not the first time I've seen someone do that 😸😅
Pro Tip: If you have to take a CRT out of a monitor or TV and you can't disconnect the yoke from the electronics in an easy way and it doesn't need to be adjusted, leave the yoke on the CRT. If you have to (or prefer to) take it off anyway, use a marker to note the original position. Great video Adrian! Thanks for posting.
The Apple IIe computer lab at my elementary school had a few of these, and of course none of us could resist scratching our fingernails on that mesh! (Most of the other Apple IIes had Amdek color monitors which had the added benefit of an amplified speaker unused by the //e, so we often connected 2 adjacent monitors to a walkman for stereo music...) Great video thanks!
I remember those mesh anti-glare filters, but I've never seen one built-in like that (not hard to do though). They worked well for monitors up to VGA, but anything SVGA or higher, the moire pattern was far too distracting, and so I stopped using them.
Obvious tip for working on CRTs, adjust the picture using a mirror so you are not reaching around, your hand could slip onto something it shouldn't. Especially with big TVs. (A tip from my old dad who was an old school TV repair man)
12:20 The exact same thing happened to me at my first job, trying to install an ethernet card in a Mac SE for the first time! I shortly thereafter learned how to safely replace a CRT tube. ;)
Monitor repair videos still give me the heebie-jeebies but they are super fascinating. I have a tiny 12" VGA monitor which goes yellow until you thwack it just right, which needs servicing but I can't muster the confidence to open it up.
Any time I had a CRT monitor apart for any repair the one thing to do is resolder all the pins on the LOPT and line output transistor, and the drive transformer, plus the low value resistors around the base circuit of the line driver, plus any diodes attached to the heatsink. They can crack from thermal cycling or vibration, creating dry joints that are near invisible, but which blow up the transistor or transformer. Same for the power supply diodes with the transformer supplies, or the switching power supply. Redo all the power diodes, power resistors, the power transformer, the coupling transformer if there for drive, and the switching transformer, along with the PTC degauss thermistor. Solved a lot of intermittent wiggle problems off the bat. Also a go around the CRT base connectors to do the joins that hold the tube socket to the CRT base board, and the transistors there, plus all the shielding band connections, used as grounds for various parts of the CRT base.
Those ring adjustments around the neck of the CRT used to be one of my go-to fixes for convergence being off on CRTs. I didn't know much about the electronics, but as a kid I knew that you could adjust the "knives" as I called them to fix the colour convergence. Lots of old TVs had bad convergence from the factory it seemed. Always bugged me and I had to fix it if I saw it was off.
I worked on the assembly line in a small computer company called Syntrex, and one of the jobs I did was adjusting and centering the picture on the monitors and installing the back casing. This was in 1985.
Love the enthusiasm, video's like these can be almost robotic but you can hear you enjoying sprucing this up. As for gushing, you gush all you like, its a job well done and the picture was pretty damn good. Well done from a sunless and cold old UK. Keep safe..
Always nice somebody tries to use a green or amber monitor instead of searching for a color one. Good that people like you still know how those worked and how to handle/adjust them. Also nice you took the info from Fran! Haven't repaired a crt in ages myself so enjoy these video's since they bring back both good and bad memories (yeah the high voltage is one of the bad things lol)
My Technical school had Apple 2e computers and we used these monitors . We had amber . Love how you save these old relics that could fade away in to the dust of history in someones garage . Or as Moe says : " car hole " .
16:07 - this is a wonderful tip/technique that is easy to forget about when trying to teach basic skills to people. This technique applies to many other situations! Almost every time you are placing a screw/bolt into an already machined (threaded) channel, you should back twist until you fall into the existing grooves before tightening. - CROSS THREADING KILLS -
You only ever forget to discharge the CRT once in your life, especially on very high voltage professional colour studio monitors. I repaired the PSU in a sony rack mount (deep metal enclosure) colour monitor at the TV transmitter site I used to work at when I was in my early 20s. I put the board back in and reached elbow deep into the cage to put the tube EHT plug back in and WHAM I copped a shock that threw me back in the control room and left a considerable amount of skin and blood on every sharp surface in that chassis!
I broke a CRT at college. Was a Prestel terminal that was basically a BBC Micro and Cub monitor in a special case with custom ROMs. We were fitting standard BBC ROMs into it and when I put the back case on I somehow broke the tube.
@@adriansdigitalbasement This was 1990/1991, so way past the life of the BBC. The 8-bits would have been practically throw away at that time. The college had a ton of original Compaq portables in the store room.
Interesting history, that this was the first Apple-branded monitor. My high school had Apple IIs, and had at least as many of these Monitor ///s as they did Monitor IIs. This explains why that was.
Regarding the CRT number, typically the P in the part number indicates the phosphor used. With televisions, P4 indicated a black and white CRT while P22 indicated a color CRT. I’m sure there are similar numbers to indicate the various phosphors used on monitor CRTs.
Awesome job! Thank You. 👍 I am pretty sure this is the monitor our high school library used for the Apple II+s that were available to use. It didn't even occur to me at the time that they were for the Apple III since I was a C64 user in 1983 so I didn't pay much attention. But that is a nice screen and it is amazing how good that monitor turned out for being as old as it is.
I have that same monitor, and it came with that same kind of smear down it. Wiping it off doesn't help, you just end up with more gunk stuck in the netting. You have to pull the picture tube out and flush the mesh out. I think the Pxx is the name of the phosphor itself. For example, P39 is a green long-persistence phosphor used in displays. The Monitor III is notorious for having a really smeary display, so it makes sense that P39 would be used in it.
From how clean the back of the CRT is you might have a low hour set. Most high hour sets will contain lots of dust. Very cool part of vintage computer history.
What's possible to use on screens to get rid of the glare instead of the mesh is the same foil wrap used by car wrappers. It's available in transparent matte finish and quite simple to wrap around the crt tube.
When I was in school in the early-mid '90s there were a lot of Monitor IIIs and some had the tilting CRT. I don't remember any of them having a dim or worn out CRT.
Fond memories with that monitor. I used it with my Apple ///. Dr. Wendell Sanders (of Apple /// fame) created a card for the Apple /// that could also drive this monitor in some sort of double resolution mode where the black lines on the interlaced image would be filled. The feature was controlled with a physical switch added to the Apple ///. Some monitors would flicker with the de-interlaced mode engaged. I tried several monitors at the local computer store until I found one that would not flicker when the de-interlaced mode engaged. Many fond memories from my days at On Three! :-) Thanks for sharing :-)
My first computer had this exact same model monitor. As a kid, I messed with all the knobs, took it a part. But I didn't touch the electronics in the CRT. I only peeked inside. I hooked it up to the family VCR and watch TV on a green display. Those were the days, when you tried everything to see what it can do. I also got yelled at for doing it.
My first computer when I was a kid was an Apple IIe with one of these that my dad bought in '84. For a while we had both this and a TV hooked up, so we could game in color but dad could actually work in 80-column applications. It's a really wonderful monitor! I've still got the whole rig in storage. Somewhere along the line the mesh got a nasty rip right in the middle of the screen. The idea of cracking the thing open and taking the mesh out entirely never occurred to me!
I had one of these, circa 1988-89. It was the first "Long-Persistence" monitor that I ever came across. Plug it into an Amiga composite port, and set it to interlaced video. You'll be surprised at the result. SERIOUSLY Long Persistence.
I had a white phosphor Monitor III, I took that anti-glare screen off of it too, it came with my apple ][ plus, it also served duty as a TV attached to a VCR, and an amplified speaker that I made from an old tape recorder with a potentiometer I harvested from an Atari paddle controller and installed into a coffee can, powered by a 6 volt lantern battery also in the coffee can. I used the same setup with my old Sega Master System :) it was a great utilitarian monitor.
In the 90's I moved my 1000 HX from a RF-Modulator going to a Magnavox 13" TV to a VM-5 TTL MDA screen and it had a very very crisp screen, but the persistence was so long that at night the screen would glow for a few hours after being turned off. Probably the light in the room charged it up.
YEP! Visible light does charge up the phosphor. My PET 4016 sits next to my modern editing PC which has a glass side and blue and red lighting inside..... just the blue leg light which shines on onto the PET CRT makes it glow for a while after I turn everything off. One can just turn off all the lights and hold a flashlight up to the green CRT, turn it off and enjoy the nice glow. It's a neat effect :-)
I am amazed how much of the tube is actually safe to touch while on. While I had seen on your earlier videos that the rings on the back are used to adjust the picture, I honestly had no idea that you can just go in there with the bare hand and adjust them.
Yeah the HV part of the tube is insulated under that anode cap. Most of the tube is painted with a matte black metallic paint that is literally at ground. (Called DAG ground) The coils themselves can have high-ish voltages through them, but they are insulated with clear enamel. If they weren't, they would all be shorting together and the monitor wouldn't work. I'd avoid the metal pins on the tube connector/neck board -- a couple of those can have a few hundred volts on some of the pins... on this monitor you can't even touch those when the connector is on though -- but some neck board PCBs on some monitors those pins are exposed so you could accidentally touch them... Some older TVs especially in 240v countries can have a hot ground chassis -- where the ground throughout the TV is actually live at mains voltage. I've personally never seen such a TV or monitor, but I know they do exist. In that case, you could get a mains shock from even touching the metal chassis ground inside the TV.....
You know, that ghosting effect would make a nice Williams memory unit. My dad's name was William so I kinda came across stuff like that a long, long time ago. Nice job with the servicing.
I picked up one of those Apple Monitor ///s real cheap and used it on my C-64 for a while. It also had a few blemishes in that cloth mesh (although it didn't bother me). I used it for my BBS computer. It was a positively wonderful screen.
I have an Amdek Color-I monitor that had this mesh. It was scuffed up and had a few bad spots so I decided to just get rid of it. Rather than removing the CRT which seems like a lot of work along with the risks to the tube and myself, I simply loosened the four screws around the corners of the tube. That allowed me to push it back away from the bezel slightly and tear away the cloth from the sides. One side did leave a bit of of the mesh that I was unable to tear off so I just tucked it up under the bezel and then tightened the tube back down.
Excellent video! I didn't know that the anti-glare mesh was so easily removable. That's good news, because of the two /// monitors I have, one has a bad scratch on it. :)
I have one of these on my //e, on my desk at work :) when I first got mine it was missing some of the rubber block feet off the bottom, so I removed the remaining one and fitted four new ones, in slightly different positions so it would sit snugly on top of my //e, which is a different width than the ///. Now I can use it with the top cover of the computer removed, as it sits on the edges, held in place by the slight lip. Thank you again for another interesting video!
Great information - In the mid 1980's school districts and colleges had thousands of these. None I've ever found have been dead, darn near indestructible.
I bought one of these to compliment my apple II+ clone that I built as a kit. There was a guy selling the apple II+ blank motherboards with all the parts to solder on... so it was a cool challenge given how young I was back then. In the early eighties, there was a flood of apple (and IBM) clone parts that hit the market, that made these PC's more affordable (although some of those parts were very cheap).
As a kid I remember a bunch of our Apple IIs had similar monitors (probably the Amdeks you mentioned) and kids would just tear the fabric apart and pull it off from the front, leaving a frayed edge around the sides.
P39 is a greenish long persistence phosphor, it also said Hitachi on the rear label. If you don't connect the dag wire, with a plastic case like this the outer graphite coating on the CRT forms one plate of a capacitor the other is the coating on the inside and the dielectric is the glass. When you power up because the outer coating is grounded nothing happens, but if you forget and leave it open the outer coating rises up to the EHT voltage and if anything is close enough it will spark over. Usually the closest item is the PCB and this is where it will jump to, very often low voltage signal components.
I found a parts list for this monitor online, and it accidentally included elements of the wiring harness that connected the TV tuner to the mainboard! So yes, this was at one time a regular Hitachi black and white television. (Search on the alternate picture tube part number, which I suspect is a white phospor version that was in the original TV.)
@adrian black, another tip for screwing stuff in, especially if you are trying to get it into a blind or hard to reach area such as crt brackets, take a little neodymium magnet or a big 1, im SURE you have enough of them just laying around from old hdds and such but find a nice small 1 about the size of your screwdriver if you have it and just stick it to the side of the shaft, that is enough to make the screw stick to the end until it is seated, and be glad you arnt adjusting a crt's color culmination!!! i did this on a 27? inch sony grand wega, the adjustment is done by adjusting 5 plastic rings around the neck of the tube, all i can say is you make a video or even do this without video-ing it, good luck, the adjustments are NOT stable for each color, if you move 1, they all move!! the best position i could find actually was nowhere near the factory marks! (take a sharpie and draw a line across all of the rings to keep as a reference of their original positions), hm... its 6 am... i forget if i brought that tv to the alley or its still somewhere in the house.. why am i not asleep
That 303 stuff is a bit on the expensive side. However, for what it does with plastic, leather, vinyl, and rubber, the price is completely worth it. That stuff is amazing!
anti-glare mesh!!! flashback...! Used to take them off VT132s back in the day: all they did was make the APs turn up the brightness, which reduced the focus. Take off the mesh and discover just how much gack and snot it could retain; turn the brightness down to 50% and return to happy dev bod. Ahhh, the memories, the potential for instant death...!
Not relative to this model, but in some monitors the screen is actually carbon fiber or blackened metal wire and is part of the CRT ground. The ground is the secondary "target" that the electron gun fires at. And helps to accellerate the beam towards the face of the crt. The primary target is the shadow mask, but the ground helps to dissipate the static charge that builds up on the leaded glass face of the CRT.
Thinking I should give you some praise for filming CRTs so well, kudos. ;) I swear the uninitiated probably see the pattern artifacts from bad filming and think that's normally visible on CRT screens.
Hi All, nice video, i remember 'back in the days' we had some type of "dumb terminals" for the accounting system - @ 1988, and they were new and the screens were very bright, the company that done the install came back about 2 months later and upgraded all ( hmm 80-90 ) of them with the anti glare - it was sort of like "flyscreen wire" that was pre cut, placed on the front of the screen and pushed with a plastic spatula into the bezel The batch next done on the floor upstairs, however this time it was a factory fix, they dissembled each screen and they had a pre cut shape with a reinforcing outer frame like the one you ripped the screen from, however this was a bit loose and they cleaned the screens and sprayed a tacky residue on the screen then pressed on the mesh filter All of these screens we much duller i think due to the more mesh or thicker material. Next OHS at work was the reflection of fluro lights on the screen, all fluros had those . how do you describe them , a type of mesh metal frame on top of the perspex diffuser to try and force the light down Also , i am sure other people commented, that computer shops and magazines were all selling some type of DIY screen filter - i always wonders the percentage of who got zapped or damaged a screen by trying to add the $10 filter After watching the yolk adjustments, i am glad my oldest VGA screen had analog adjustments for up / down / left / right / shink / strech / rotate - actually now i remember on the yoke some of those ring adjusters actually done a brightness Regards George
P39 and P42 are both phosphor colour and persistence, as some were very fast decay, while others had a lot of afterglow. A lot of the dimness is also caused by resistors in the screen and grid circuits drifting high in value, along with the pots as well. Typically suspect all resistors over 10k in the high voltage side, so basically all resistors around the LOPT and by the controls, check for resistance in circuit, as a reading lower than the value is typically fine, but higher you need to replace it. Use the right resistors, you need the correct power and voltage rating on the replacement resistors.
Hey Adrian, I picked up an Apple IIE and the same monitor for $40 from a junk collector on Craigslist. I don't think he had any idea what he had, it was in pretty rough shape, so I took the whole thing apart, re-capped the PSU, did lots of scrubbing in the sink and wore out one magic eraser. I found a compatible Mac Keyboard on EBay and stole key switches from it (the keyboard was the hardest part to restore)... For the monitor I left the yoke control and de-soldered the connectors to it and gave the whole thing a good cleaning, the anti-glare was in worse shape than yours. So I went to Michaels and found some really fine lace that I stretched back over the frame, it's not perfect but it does look vastly better. The best part is the whole thing cost me maybe $100 total in parts and some labor and I now have a fully functional IIE with the Apple III monitor. Keep up the good work, I look forward to your videos. Also you might want to check out the BackBit for the C64, I ordered mine and if it's as good as I'm hoping I'll be grabbing a second one for my C64 that sits on my electronics workbench...
It wouldn't really surprise me too that it's just a chassis derived from a TV set, some TVs had their tuners that output éd CVBS (composite video, which is also what this monitor takes), on these TVs you can sometimes directly tap riiiight after the tuner and send CVBS directly to it. Though not all sets are like that. I've also seen a "monitor" that was just a mere B&W TV fitted with a green, long persistence phosphor tube and a cover above the VHF/UHF knobs and the relevant buttons (you only had the contrast/brightness knobs on it). I know LGR restored one of these "monitors" in a video, but I can't, for the life of me, remember which one. 8:40 FWIW, if you don't really care about the tube or already have a replacement you can use a CRT rejuvenator on it as a last ditch effort, though be warned that it is like reflowing a BGA chip with a oven or a heat gun, it's only going to be temporary. I've also saw some people cranking the SCREEN (or G2) voltage, but this often results in retrace lines appearing.
Yeah, i think so too; in fact i have an old Sharp monitor that looks _exactly_ like one of their domestic TV sets. I think the 8-Bit Guy also mentioned a similar thing in one of his Tandy TRS-80 videos.
I had an amber monitor for my Tandy 1000A (bought the system used) that had one of those mesh screens. I didn't dismantle the chassis, I ended up running a razor blade around the bezel to cut it off (was filthy the same way yours was). And after all the videos I've seen of people working on CRTs and tube TVs, I can only presume I was either stupid and/or lucky the time I replaced the flyback transformer on an old IBM VGA monitor. (discharge the anode cap?? discharge filter capacitors?? What's that mean??). I do recall the way TV techs used to do adjustments on TVs when they did it on a regular basis. They'd have a large mirror set up on their workbench so they could adjust the picture without having to go back & forth from front to back.
I use 303 on the tires and dash of my Bronco that sits all summer in Arizona while also covered with UV blocking covers to keep as much UV from breaking them down as possible.
LOL. Strange story -- one day I went to roll my trash can back in after the truck had come by and someone had left it on top the trash can. I left it outside to dry off (it had been raining) and then washed it twice in the washing machine. I now use it for purposes like this -- it is more interesting than my own personal frayed towels I was using... Boring solid colors towels!
I got one of these given to me in literal pieces. I think someone planned to scrap it but for some reason it never happened. It had sat in pieces in this guys yard out in the weather for who knows how long. I brought the pieces home and cleaned everything and wired up a new cord and I'll be Damned if it didn't fire right up. I still use it over a year later. Great picture on these but the motion blur is a bit rough for games. Ideal for office work though
![Apple ][ plus extreme cleaning + testing the Panasonic Monitor](http://i.ytimg.com/vi/1iCLdbF1sgw/mqdefault.jpg)
![Apple ][ plus: 8304 replacement from AliExpress, more keyboard fixes, and a huge surprise!](/img/n.gif)
3:45 the sticker on the back says made for Apple by Hitachi! 😁
Crazy, but Apple always outsource their manufacturing, they always have. Makes it quicker (not cheaper obv lol)
@@jameslewis7620 Most computer companies did for monitors. CRT construction is far enough removed from everything else involved in making a computer that even highly-integrated companies tended to pay a TV company to make them a display.
Yes. Compaq for instance used Kyocera for their CRT monitors.
@@stanburton6224 TI used both Zenith and Panasonic during their brief foray into home computing.
Yep, in Europe a lot of monitors were actually made by Philips, or at least had Philips picture tubes
According to the "Phosphor Handbook", P39 and P42 are both "yellowish-green" in color. The P-numbers are the EIA designation for the different phosphor types.
"Take your first shot now."
Uh-oh, he's on to us.
LOL
I'm way ahead.
Hit me with your best shot! Fire awaaaaaay!
@Adrian's Digital Basement .. if you want to put a "new" anti glare filter at 13:50 ... you know for historical proposites or something like that.. you can get one from this vintage Anti-glare fiber "fultra fine nylon mesh" (image 4)
»» www.ebay.com/itm/Vintage-Computer-CRT-Screen-Anti-glare-Color-Monitor-Filter-1988-MAC-IBM-NEC-/174168256917
When I was a kid my friend had a Monitor /// for his Apple IIE, and I fell in love with the color of that green monochrome tube. I only had a b/w television to use as a monitor for my Atari 400, and by comparison the Apple's green was way, way sexier (a little bit ironic too, as my Atari actually had the better color and grayscale capability). I liked the green Apple display aesthetic so much that I used to POKE my school's C64s to green text on a borderless black background every time I powered mine on. To me nothing recalls the feeling of early home computing more than a monochrome display.
In my nearly 45 years on this planet, I have never ever been disappointed with anything that said Hitachi on it. Looks wonderful!
Had a "lemon" of a hdd from hitachi (came in a toshiba laptop) once, several diagnostics told me it was faulted and would soon die. I was still running that faulted drive about 6, 7 years later. It hadn't gotten any worse, still worked fine, read wrote, and absolutely never crashed. Every review of that drive i found said it was unreliable. I found that not to be the case. I just finally retired it about 2 weeks ago, as i had built an lfs system on it and want to rescue it off of it before it does actually stop working. Do indeed respect hitachi, even the lemons never die.
I bought 4 30GB Deskstars about 17 years ago. I had them in RAID5 so if something happened I could recover stuff. Just retired them almost a year ago (they were holding unimportant stuff lately) still going strong... I think it was only a certain drive from the IBM days that had problems, but it tarnished the name forever.
16:00 re: going backwards before forwards when screwing in. I've always done that since I was a little kid. Just seemed to make sense that I didn't want to wreck the threads. (Before I figured that out I definitely stripped some screws.)
This is great advice. I learned the same trick about 20 years ago from a plumber working on water softeners. Been doing it ever since.
@@jason50146 in one of the videos on my channel I found an old HP, and inside were a few expansion cards.
Now, instead of taking their time, the previous owner had strong-armed new threads into the post at a 45 degree angle rather than bother to seat the card properly.
Sadly, that was not the first time I've seen someone do that 😸😅
me to, have to do that with plastic devices.
Pro Tip: If you have to take a CRT out of a monitor or TV and you can't disconnect the yoke from the electronics in an easy way and it doesn't need to be adjusted, leave the yoke on the CRT. If you have to (or prefer to) take it off anyway, use a marker to note the original position.
Great video Adrian! Thanks for posting.
You made a major score on that monitor. Amazing at the quality for its age. Perfect video between tech and safety.
The Apple IIe computer lab at my elementary school had a few of these, and of course none of us could resist scratching our fingernails on that mesh! (Most of the other Apple IIes had Amdek color monitors which had the added benefit of an amplified speaker unused by the //e, so we often connected 2 adjacent monitors to a walkman for stereo music...) Great video thanks!
I remember those mesh anti-glare filters, but I've never seen one built-in like that (not hard to do though). They worked well for monitors up to VGA, but anything SVGA or higher, the moire pattern was far too distracting, and so I stopped using them.
Obvious tip for working on CRTs, adjust the picture using a mirror so you are not reaching around, your hand could slip onto something it shouldn't. Especially with big TVs. (A tip from my old dad who was an old school TV repair man)
12:20 The exact same thing happened to me at my first job, trying to install an ethernet card in a Mac SE for the first time! I shortly thereafter learned how to safely replace a CRT tube. ;)
Monitor repair videos still give me the heebie-jeebies but they are super fascinating. I have a tiny 12" VGA monitor which goes yellow until you thwack it just right, which needs servicing but I can't muster the confidence to open it up.
Ahh the good old "percussive maintenance" hehe
Any time I had a CRT monitor apart for any repair the one thing to do is resolder all the pins on the LOPT and line output transistor, and the drive transformer, plus the low value resistors around the base circuit of the line driver, plus any diodes attached to the heatsink. They can crack from thermal cycling or vibration, creating dry joints that are near invisible, but which blow up the transistor or transformer. Same for the power supply diodes with the transformer supplies, or the switching power supply. Redo all the power diodes, power resistors, the power transformer, the coupling transformer if there for drive, and the switching transformer, along with the PTC degauss thermistor. Solved a lot of intermittent wiggle problems off the bat. Also a go around the CRT base connectors to do the joins that hold the tube socket to the CRT base board, and the transistors there, plus all the shielding band connections, used as grounds for various parts of the CRT base.
wonder how many of those hairline cracks were caused by people banging their TV to "fix" it...
It's only 8am and I'm already doing Deoxit shots... 😂
LMAO
Croissant
The image is so clear, really sharp, i love it
My father always taught me to screw backwards before going clockwise. Glad to hear I'm not the only one who does it, it's second nature now.
the "going backwards a bit first" thing to the screws is great advice for most all screws/bolts/threaded stuff/etc.
Those ring adjustments around the neck of the CRT used to be one of my go-to fixes for convergence being off on CRTs. I didn't know much about the electronics, but as a kid I knew that you could adjust the "knives" as I called them to fix the colour convergence. Lots of old TVs had bad convergence from the factory it seemed. Always bugged me and I had to fix it if I saw it was off.
Nice. .it's certainly a lot harder to adjust those properly on a color set versus monochrome where it simply moves the picture around.
I worked on the assembly line in a small computer company called Syntrex, and one of the jobs I did was adjusting and centering the picture on the monitors and installing the back casing. This was in 1985.
Love the enthusiasm, video's like these can be almost robotic but you can hear you enjoying sprucing this up. As for gushing, you gush all you like, its a job well done and the picture was pretty damn good. Well done from a sunless and cold old UK. Keep safe..
Always nice somebody tries to use a green or amber monitor instead of searching for a color one. Good that people like you still know how those worked and how to handle/adjust them. Also nice you took the info from Fran! Haven't repaired a crt in ages myself so enjoy these video's since they bring back both good and bad memories (yeah the high voltage is one of the bad things lol)
15:59 Great piece of advice for reinstalling self tapping screws in these older plastic cases - thanks for sharing!
Isn't that how you insert all screws? That's how I've always done it
My Technical school had Apple 2e computers and we used these monitors . We had amber . Love how you save these old relics that could fade away in to the dust of history in someones garage . Or as Moe says : " car hole " .
16:07 - this is a wonderful tip/technique that is easy to forget about when trying to teach basic skills to people. This technique applies to many other situations! Almost every time you are placing a screw/bolt into an already machined (threaded) channel, you should back twist until you fall into the existing grooves before tightening.
- CROSS THREADING KILLS -
You only ever forget to discharge the CRT once in your life, especially on very high voltage professional colour studio monitors. I repaired the PSU in a sony rack mount (deep metal enclosure) colour monitor at the TV transmitter site I used to work at when I was in my early 20s. I put the board back in and reached elbow deep into the cage to put the tube EHT plug back in and WHAM I copped a shock that threw me back in the control room and left a considerable amount of skin and blood on every sharp surface in that chassis!
I broke a CRT at college. Was a Prestel terminal that was basically a BBC Micro and Cub monitor in a special case with custom ROMs. We were fitting standard BBC ROMs into it and when I put the back case on I somehow broke the tube.
It's such a terrible feeling. At least back then replacement tubes were easy to come by though.
@@adriansdigitalbasement This was 1990/1991, so way past the life of the BBC. The 8-bits would have been practically throw away at that time. The college had a ton of original Compaq portables in the store room.
Interesting history, that this was the first Apple-branded monitor. My high school had Apple IIs, and had at least as many of these Monitor ///s as they did Monitor IIs. This explains why that was.
Very interesting video. CRT repair and adjustment is fast becoming a lost art
Regarding the CRT number, typically the P in the part number indicates the phosphor used. With televisions, P4 indicated a black and white CRT while P22 indicated a color CRT. I’m sure there are similar numbers to indicate the various phosphors used on monitor CRTs.
Awesome job! Thank You. 👍 I am pretty sure this is the monitor our high school library used for the Apple II+s that were available to use. It didn't even occur to me at the time that they were for the Apple III since I was a C64 user in 1983 so I didn't pay much attention. But that is a nice screen and it is amazing how good that monitor turned out for being as old as it is.
I have that same monitor, and it came with that same kind of smear down it. Wiping it off doesn't help, you just end up with more gunk stuck in the netting. You have to pull the picture tube out and flush the mesh out. I think the Pxx is the name of the phosphor itself. For example, P39 is a green long-persistence phosphor used in displays. The Monitor III is notorious for having a really smeary display, so it makes sense that P39 would be used in it.
27:17 Adrian, you get to gush. Great work and great results.
From how clean the back of the CRT is you might have a low hour set. Most high hour sets will contain lots of dust. Very cool part of vintage computer history.
What's possible to use on screens to get rid of the glare instead of the mesh is the same foil wrap used by car wrappers. It's available in transparent matte finish and quite simple to wrap around the crt tube.
I always go backwards first when putting screws back in, not just with plastic. Only recently found Blanche's channel but I enjoy it.
When I was in school in the early-mid '90s there were a lot of Monitor IIIs and some had the tilting CRT. I don't remember any of them having a dim or worn out CRT.
Fond memories with that monitor. I used it with my Apple ///. Dr. Wendell Sanders (of Apple /// fame) created a card for the Apple /// that could also drive this monitor in some sort of double resolution mode where the black lines on the interlaced image would be filled. The feature was controlled with a physical switch added to the Apple ///. Some monitors would flicker with the de-interlaced mode engaged. I tried several monitors at the local computer store until I found one that would not flicker when the de-interlaced mode engaged. Many fond memories from my days at On Three! :-) Thanks for sharing :-)
My first computer had this exact same model monitor. As a kid, I messed with all the knobs, took it a part. But I didn't touch the electronics in the CRT. I only peeked inside. I hooked it up to the family VCR and watch TV on a green display. Those were the days, when you tried everything to see what it can do. I also got yelled at for doing it.
My first computer when I was a kid was an Apple IIe with one of these that my dad bought in '84. For a while we had both this and a TV hooked up, so we could game in color but dad could actually work in 80-column applications. It's a really wonderful monitor! I've still got the whole rig in storage.
Somewhere along the line the mesh got a nasty rip right in the middle of the screen. The idea of cracking the thing open and taking the mesh out entirely never occurred to me!
I had this monitor on my Apple II+ and distinctly remember how sharp it was and the texture on the screen.
I had one of these, circa 1988-89. It was the first "Long-Persistence" monitor that I ever came across. Plug it into an Amiga composite port, and set it to interlaced video. You'll be surprised at the result. SERIOUSLY Long Persistence.
I had a white phosphor Monitor III, I took that anti-glare screen off of it too, it came with my apple ][ plus, it also served duty as a TV attached to a VCR, and an amplified speaker that I made from an old tape recorder with a potentiometer I harvested from an Atari paddle controller and installed into a coffee can, powered by a 6 volt lantern battery also in the coffee can. I used the same setup with my old Sega Master System :) it was a great utilitarian monitor.
46 years old, I remember it well!
when i was in school they had the apples with monitor where you tilt the tube like you mentioned, i have an 1986 iie with the color monitor.
Thank you for spreading the screw in plastic trick !
In the 90's I moved my 1000 HX from a RF-Modulator going to a Magnavox 13" TV to a VM-5 TTL MDA screen and it had a very very crisp screen, but the persistence was so long that at night the screen would glow for a few hours after being turned off. Probably the light in the room charged it up.
YEP! Visible light does charge up the phosphor. My PET 4016 sits next to my modern editing PC which has a glass side and blue and red lighting inside..... just the blue leg light which shines on onto the PET CRT makes it glow for a while after I turn everything off. One can just turn off all the lights and hold a flashlight up to the green CRT, turn it off and enjoy the nice glow. It's a neat effect :-)
I am amazed how much of the tube is actually safe to touch while on. While I had seen on your earlier videos that the rings on the back are used to adjust the picture, I honestly had no idea that you can just go in there with the bare hand and adjust them.
Yeah the HV part of the tube is insulated under that anode cap. Most of the tube is painted with a matte black metallic paint that is literally at ground. (Called DAG ground) The coils themselves can have high-ish voltages through them, but they are insulated with clear enamel. If they weren't, they would all be shorting together and the monitor wouldn't work. I'd avoid the metal pins on the tube connector/neck board -- a couple of those can have a few hundred volts on some of the pins... on this monitor you can't even touch those when the connector is on though -- but some neck board PCBs on some monitors those pins are exposed so you could accidentally touch them...
Some older TVs especially in 240v countries can have a hot ground chassis -- where the ground throughout the TV is actually live at mains voltage. I've personally never seen such a TV or monitor, but I know they do exist. In that case, you could get a mains shock from even touching the metal chassis ground inside the TV.....
That reverse spin on the screws is a great tip. Thanks to both you and your source, Fran.
You know, that ghosting effect would make a nice Williams memory unit. My dad's name was William so I kinda came across stuff like that a long, long time ago. Nice job with the servicing.
I picked up one of those Apple Monitor ///s real cheap and used it on my C-64 for a while. It also had a few blemishes in that cloth mesh (although it didn't bother me). I used it for my BBS computer. It was a positively wonderful screen.
Nice job! Thanks for showing the whole process and your attention to detail.
6:57 First DeoxIT reference.
17:40 First DeoxIT use.
Im thinking Adrian owns stock in the company...=p
@@stanburton6224 they need to sponsor him and send an entire case or 55 gallon drum!!
I have an Amdek Color-I monitor that had this mesh. It was scuffed up and had a few bad spots so I decided to just get rid of it. Rather than removing the CRT which seems like a lot of work along with the risks to the tube and myself, I simply loosened the four screws around the corners of the tube. That allowed me to push it back away from the bezel slightly and tear away the cloth from the sides. One side did leave a bit of of the mesh that I was unable to tear off so I just tucked it up under the bezel and then tightened the tube back down.
Excellent video! I didn't know that the anti-glare mesh was so easily removable. That's good news, because of the two /// monitors I have, one has a bad scratch on it. :)
I remember those monitors. Nostalgic...
I have one of these on my //e, on my desk at work :) when I first got mine it was missing some of the rubber block feet off the bottom, so I removed the remaining one and fitted four new ones, in slightly different positions so it would sit snugly on top of my //e, which is a different width than the ///. Now I can use it with the top cover of the computer removed, as it sits on the edges, held in place by the slight lip. Thank you again for another interesting video!
I just recieved one of these for free, I couldn't be more excited. I hooked it up to my Coleco ADAM and Atari XEGS to test it and it looks amazing.
Great information - In the mid 1980's school districts and colleges had thousands of these. None I've ever found have been dead, darn near indestructible.
All the best stuff is made in Japan.
I bought one of these to compliment my apple II+ clone that I built as a kit. There was a guy selling the apple II+ blank motherboards with all the parts to solder on... so it was a cool challenge given how young I was back then. In the early eighties, there was a flood of apple (and IBM) clone parts that hit the market, that made these PC's more affordable (although some of those parts were very cheap).
As a kid I remember a bunch of our Apple IIs had similar monitors (probably the Amdeks you mentioned) and kids would just tear the fabric apart and pull it off from the front, leaving a frayed edge around the sides.
P39 is a greenish long persistence phosphor, it also said Hitachi on the rear label.
If you don't connect the dag wire, with a plastic case like this the outer graphite coating on the CRT forms one plate of a capacitor the other is the coating on the inside and the dielectric is the glass.
When you power up because the outer coating is grounded nothing happens, but if you forget and leave it open the outer coating rises up to the EHT voltage and if anything is close enough it will spark over. Usually the closest item is the PCB and this is where it will jump to, very often low voltage signal components.
I'm a Mac SE tube braker as well. Did it once and never did it again. After the back cover comes off... Pull the CRT tube socket ...
Thanks for the link to the squeezy bottles. Mr Carlson is always using them and I wanted some to use with my flux and lubricants.
This was immensely satisfying to watch, rock on sir!
"...the usual warnings like high volatage and dangerous to work on a CRT an bla bla bla bla bla"
- Made my day :-D
I found a parts list for this monitor online, and it accidentally included elements of the wiring harness that connected the TV tuner to the mainboard! So yes, this was at one time a regular Hitachi black and white television. (Search on the alternate picture tube part number, which I suspect is a white phospor version that was in the original TV.)
Absolutely salute you for skipping the anode cap removal and discharge. :)
@adrian black, another tip for screwing stuff in, especially if you are trying to get it into a blind or hard to reach area such as crt brackets, take a little neodymium magnet or a big 1, im SURE you have enough of them just laying around from old hdds and such but find a nice small 1 about the size of your screwdriver if you have it and just stick it to the side of the shaft, that is enough to make the screw stick to the end until it is seated, and be glad you arnt adjusting a crt's color culmination!!! i did this on a 27? inch sony grand wega, the adjustment is done by adjusting 5 plastic rings around the neck of the tube, all i can say is you make a video or even do this without video-ing it, good luck, the adjustments are NOT stable for each color, if you move 1, they all move!! the best position i could find actually was nowhere near the factory marks! (take a sharpie and draw a line across all of the rings to keep as a reference of their original positions), hm... its 6 am... i forget if i brought that tv to the alley or its still somewhere in the house.. why am i not asleep
That 303 stuff is a bit on the expensive side. However, for what it does with plastic, leather, vinyl, and rubber, the price is completely worth it. That stuff is amazing!
Good job Adrian!
anti-glare mesh!!! flashback...! Used to take them off VT132s back in the day: all they did was make the APs turn up the brightness, which reduced the focus. Take off the mesh and discover just how much gack and snot it could retain; turn the brightness down to 50% and return to happy dev bod. Ahhh, the memories, the potential for instant death...!
Any time I take something apart that's older, I really enjoy the tactile feel of the crack of a screw releasing for the first time in years.
Especially if it's never been opened before :-)
I usually place a mirror in front of the monitor when i adjust and fine tune the settings to make it easier.😊
What you don't like reaching around blindly pawing all that high voltage stuff?
Oh, I had one of these for my Commodore 64 back in the early 80's. Got the Monitor /// second-hand. Good times!
Not relative to this model, but in some monitors the screen is actually carbon fiber or blackened metal wire and is part of the CRT ground. The ground is the secondary "target" that the electron gun fires at. And helps to accellerate the beam towards the face of the crt. The primary target is the shadow mask, but the ground helps to dissipate the static charge that builds up on the leaded glass face of the CRT.
Thinking I should give you some praise for filming CRTs so well, kudos. ;) I swear the uninitiated probably see the pattern artifacts from bad filming and think that's normally visible on CRT screens.
Hi All, nice video, i remember 'back in the days' we had some type of "dumb terminals" for the accounting system - @ 1988, and they were new and the screens were very bright, the company that done the install came back about 2 months later and upgraded all ( hmm 80-90 ) of them with the anti glare - it was sort of like "flyscreen wire" that was pre cut, placed on the front of the screen and pushed with a plastic spatula into the bezel
The batch next done on the floor upstairs, however this time it was a factory fix, they dissembled each screen and they had a pre cut shape with a reinforcing outer frame like the one you ripped the screen from, however this was a bit loose and they cleaned the screens and sprayed a tacky residue on the screen then pressed on the mesh filter
All of these screens we much duller i think due to the more mesh or thicker material.
Next OHS at work was the reflection of fluro lights on the screen, all fluros had those . how do you describe them , a type of mesh metal frame on top of the perspex diffuser to try and force the light down
Also , i am sure other people commented, that computer shops and magazines were all selling some type of DIY screen filter - i always wonders the percentage of who got zapped or damaged a screen by trying to add the $10 filter
After watching the yolk adjustments, i am glad my oldest VGA screen had analog adjustments for up / down / left / right / shink / strech / rotate - actually now i remember on the yoke some of those ring adjusters actually done a brightness
Regards
George
I always loved the mono CRT's. Compared to the colour monitors of the day, they were so much easier to read text on.
Yeah the sharpness of these monitor is quite amazing -- especially compared to the fuzzy TV quality pictures most of us were seeing elsewhere.
P39 and P42 are both phosphor colour and persistence, as some were very fast decay, while others had a lot of afterglow.
A lot of the dimness is also caused by resistors in the screen and grid circuits drifting high in value, along with the pots as well. Typically suspect all resistors over 10k in the high voltage side, so basically all resistors around the LOPT and by the controls, check for resistance in circuit, as a reading lower than the value is typically fine, but higher you need to replace it. Use the right resistors, you need the correct power and voltage rating on the replacement resistors.
If you have an Amiga this is an excellent monitor for interlaced high res. The phosphor is so long there is no flicker.
Great process. Time to do this to my KFest 2019 Monitor ///!
Henry Winkler’s character uses this monitor in the 1982 movie ´Night Shift’.
Fascinating, I've never heard/seen this before in all my years with computers, an actual anti-glare cloth.
Hey Adrian, I picked up an Apple IIE and the same monitor for $40 from a junk collector on Craigslist. I don't think he had any idea what he had, it was in pretty rough shape, so I took the whole thing apart, re-capped the PSU, did lots of scrubbing in the sink and wore out one magic eraser. I found a compatible Mac Keyboard on EBay and stole key switches from it (the keyboard was the hardest part to restore)...
For the monitor I left the yoke control and de-soldered the connectors to it and gave the whole thing a good cleaning, the anti-glare was in worse shape than yours. So I went to Michaels and found some really fine lace that I stretched back over the frame, it's not perfect but it does look vastly better. The best part is the whole thing cost me maybe $100 total in parts and some labor and I now have a fully functional IIE with the Apple III monitor.
Keep up the good work, I look forward to your videos. Also you might want to check out the BackBit for the C64, I ordered mine and if it's as good as I'm hoping I'll be grabbing a second one for my C64 that sits on my electronics workbench...
This video was very interesting and entertaining. As always Adrian, Thank you! Multiple thumbs up.🙂
It wouldn't really surprise me too that it's just a chassis derived from a TV set, some TVs had their tuners that output éd CVBS (composite video, which is also what this monitor takes), on these TVs you can sometimes directly tap riiiight after the tuner and send CVBS directly to it. Though not all sets are like that.
I've also seen a "monitor" that was just a mere B&W TV fitted with a green, long persistence phosphor tube and a cover above the VHF/UHF knobs and the relevant buttons (you only had the contrast/brightness knobs on it). I know LGR restored one of these "monitors" in a video, but I can't, for the life of me, remember which one.
8:40 FWIW, if you don't really care about the tube or already have a replacement you can use a CRT rejuvenator on it as a last ditch effort, though be warned that it is like reflowing a BGA chip with a oven or a heat gun, it's only going to be temporary. I've also saw some people cranking the SCREEN (or G2) voltage, but this often results in retrace lines appearing.
Yeah, i think so too; in fact i have an old Sharp monitor that looks _exactly_ like one of their domestic TV sets. I think the 8-Bit Guy also mentioned a similar thing in one of his Tandy TRS-80 videos.
I miss doing CRT repair. I am a relative recent subscriber and didn't know this was also something you did. Nice surprise.
I had an amber monitor for my Tandy 1000A (bought the system used) that had one of those mesh screens. I didn't dismantle the chassis, I ended up running a razor blade around the bezel to cut it off (was filthy the same way yours was).
And after all the videos I've seen of people working on CRTs and tube TVs, I can only presume I was either stupid and/or lucky the time I replaced the flyback transformer on an old IBM VGA monitor. (discharge the anode cap?? discharge filter capacitors?? What's that mean??).
I do recall the way TV techs used to do adjustments on TVs when they did it on a regular basis. They'd have a large mirror set up on their workbench so they could adjust the picture without having to go back & forth from front to back.
A P39 phosphor is a green phosphor according to my phosphor list. P42 does not appear in my list or any I have seen. Hope that helps a little.
Yes, P42 is a green phosphor, P39 is the white phosphor. There are more tubes listed on the french one because the x-ray emissions laws are different
I use 303 on the tires and dash of my Bronco that sits all summer in Arizona while also covered with UV blocking covers to keep as much UV from breaking them down as possible.
i love the digital basement
Beautiful screen. Must see if I can find some of that 303 stuff over here 🇮🇪. Thanks Adrian 👍
where did that towel come from?....80s??..looks like 60s or 70s...I love it!..where can i get one?
Mothers everywhere save those for when you throw up.
LOL. Strange story -- one day I went to roll my trash can back in after the truck had come by and someone had left it on top the trash can. I left it outside to dry off (it had been raining) and then washed it twice in the washing machine. I now use it for purposes like this -- it is more interesting than my own personal frayed towels I was using... Boring solid colors towels!
@@adriansdigitalbasement Sounds like the textile version of the fruitcake that no one wants so they keep passing it on to the next person.
I am very familiar with the Monitor ///. When my dad bought our old Apple //e, the guy who sold it to him included a Monitor ///.
I got one of these given to me in literal pieces. I think someone planned to scrap it but for some reason it never happened. It had sat in pieces in this guys yard out in the weather for who knows how long. I brought the pieces home and cleaned everything and wired up a new cord and I'll be Damned if it didn't fire right up. I still use it over a year later. Great picture on these but the motion blur is a bit rough for games. Ideal for office work though
Really interesting video! That monitor is a beauty!
Gotta love bodily fluids on the hardware...
Your "This..." in the intro made me think for a second that I was watching a Doug DeMuro car review.
Adrian's gonna show us his quirks and features, then we're gonna take him out on the road and give him a dougscore
petey 815 Needs more tshirts tho