A lot of the amiga stores sell new membranes as well as a more sturdy replacement. They also sell a rom fix that just plugs into the rom socket for anything above 1.3
As started Adrian, When I was in my teens (early 2000's), I had an old membrane keyboard from my parents compaq presario 5000t. One day a whole group of keys stopped working. I was able to disassemble the keyboard and using a multimeter I found where the trace had broken apart. (unsure what caused it). Soldering was out of the question on the thin plastic membrane, BUT I used some rear window heater grid paint available from auto parts stores. Comes in a real small bottle with a paintbrush. Painted a few coats over the split and reassembled the keyboard. Worked like a charm.
This is definitely the way I would recommend unless it is a dual layer film membrane (sometimes with a third separating layer). Separating the layers can destroy them sometimes depending on how it is made. Single layer membranes can usually be fixed as long as the ribbon cable connector is still good. How long it will last is hard to say, but usually quite a while. Conductive paint is pretty awesome. Needless to say, be careful when doing this because that stuff can make a terrible mess on a board and it is conductive.
Please take your time, Adrian. 2 videos per week is a lot and if you skip one, now and then, noone will be angry. There is no need to ever rush things.
It's nice to see a piece of ITALIAN software running on an American Amiga. :) Logica was an Italian company which produced accessories for the Commodore Amiga line of computers. Amiga had a huge success in Italy back in the day.
I repaired my A500 keyboard with silver contact paint. It's about as expensive as printer ink, but does the job fixing hairline cracks in flatflex stuff if it is under low mechanical stress. So once the membrane is inside the sandwich again, it should be fine. Hint though: let the paint dry, it will not conduct properly when still wet. :) (edit: I still haven't edited the video for that one; it's my oldest "eventually" spare content one but on mine one of the Amiga keys was dead, and you need both for the reset combo)
The only way I know of to fix one of the A500 membrane keyboards is to seperate the layers and clean the contacts with a pencil eraser. It's risky but does work very well in most cases. If you find carbon pads benieth the keys I would use isopropanol and a cue-tip or other cotton swab. For the carbon pad on the key side, just rub it acros some paper until it leaves a good solid skidmark that is the same width as the pad. Note that this trick also works for TV remotes where keys stop working.
To repair Atari membrane keyboards I've used silver conductive paint, for durability I've added a little superglue on top of the silver conductive paint.
Funny too is there is no easy to find answer to this problem even today -- knowledge is there but Google search results give mixed and unclear results.
I really could have done with something like that S-Video adapter back in the day. That combo of the 1702 and the A500 (rev5) was my setup. I used the colour composite out of the A520 modulator. Which was ok but slightly blurrier than I would have liked.
I’ve repaired a few amiga keyboards. Yes there are a few options for membrane replacements. The one I favour is the “hard” membrane replacements, readily available in the UK, sadly I’m not sure of availability in the US. But I’d try fixing first. Having removed the 40million screws (slightly larger screws around the pcb controller to watch for), remove the membrane, place on flat surface and gently wipe with water or if feeling brave some glass cleaner can work well. Sometimes I’ve needed to refurbish the little plunger, some conductive paint can be used (Liquiwire 50mL Electrically conductive paint for PCB & electric circuit repair from Amazon) is what I’ve used with success, dip the plunger into it and let dry. As you say Esc and F1 not working when the rest work usually points to plunger or dirt on membrane. Before going to the bother of getting the conductive paint, try swapping a couple of plungers around. Hope this helps.
Always good value. Keyboard Membrane Repair, FWVLIW: Just don't, you'll be much happier! ...but if you must, or just don't have an option: (nobody makes replacement membranes for my favourite retro system) 1) Find the schematic and test the leys. This will likely tell you if the issue(s) is/are with: -The connection with the with the computer (I hope you checked that first!) -The controller or it's connections (hopefully the socket or dry solder joints, not the chip itself) -One (or more) of the main row/column traces on the membrane (repairs are easier if any cracks aren't near the keys) -An individual key or local trace(s) 2) Carefully disassemble the keyboard: -Dry clean the key mechanisms and partially reassemble. If you're very lucky it was just guck / grit -Brush down the outsides of the membrane ONLY and give it a gentle flap. Test again, maybe just a bit of grit / guck -Being VERY CAREFUL look for any cracks in the FULL LENGTH of likely tracks by continuity testing and then magnification to find the exact spot(s) -No clue? AMAZINGLY CAREFULLY push a FLATTENED cotton bud tip between the membranes where the key presses and GENTLY rub both sides (It may be the pads have a bit of build-up that is preventing conduction, hopefully you shifted it without scrubbing off the usually very delicate film) -If you found a cracked trace you can effect a repair with a product like Wire Glue, Silver contact paint, or similar... a) It's amazingly important NOT to daub it on - claggy lumps ruin membranes. Whisker-thin dab, dry, test, more if necessary... b) If the crack(s) is anywhere near a key actuation spot you are almost certainly NOT going to effect a successful repair, but try if you must. Second last resort: If it really looks like all the traces are good, it's just that the pads under the key(s) are worn out you may get away with the old drawing on the pads with a soft led pencil trick, taking care NOT to distort or scratch the plastic. If this works at all it probably won't last long. Alternately a very VERY thin layer of Wire Glue or similar might help. You can even try applying a small circle of gold leaf!!! (expensive, horribly fiddly) Last (first?) resort: You could design your own replacement keyboard PCB to interface with the old logic. Not as hard as you might think - there are online resources to help. Two options: a) A PCB with SMT tact-switches or dome switches to go where to old membrane lived. If there's room, great. If not you may need to sand a little off the bottoms of the old key plungers - this will leave you with a seemingly authentic keyboard that's more reliable and a better action. Best to order a PCB thinner than the standard 1.6mm if you can, some manufacturers will even do flexible ones but they are horribly expensive and they aren't necessary. An awesome mod for the old rubber-key ZX Spectrum, but it works for many mechanical keyboards too. The old membrane will serve as a template for your layout. b) A complete new mechanism using modern mechanical switches - more fashionable and possibly more robust and future-proof. But modding old keycaps to fit new switches is a bugger, as is finding new keycaps that look the part. Then there's the whole "Am I going to have to design / program my own controller too?" I hope that helps someone.
On the flickering video check the two large caps near the video port. They tend to go bad and can short out. They will also over heat the resistors. I've had that occur on two of my version five boards
We've had rain for most of a week here in Texas, but no basements! The ground is wrong on one way or another for basements, but here it's limestone like a foot or two below the ground.
If I remember correctly those mitsumi keyboard membranes are actually single layer and there are rubber plungers which make a connection between 2 pads to register the keypress (in the same way as the c64 keyboard works). I'd be tempted to take the keyboard apart and check that the issue isn't simply that the rubber contacts on the bottom of the plungers are dirty for those two keys and hence are not making a good connection or that there isn't just a bit of fluff in there thats preventing those keys from making a good connection.
@@adriansdigitalbasement2 I think the samsung ones might be two layer, but yeah, I'm pretty sure the mitsumi ones are just contacts on a membrane. I'm guessing it saved commodore a few pennies. There are now aftermarket solutions where you can replace the membrane with a proper pcb solution instead. I've never tried those, so don't know whether its an upgrade or not though.
This exactly. Don't discount the rubber on the posts. I was given (5) A500 keyboards to repair and only one had a bad membrane but the rest had various keys that did not work and in all of those cases it was the rubber that lost its conductivity. Replacing them fixed all of them. If it does turn out to be the membrane you can purchase new replacements including a PCB version that uses a very thin PCB and gold contacts. I have used both solutions and they both work great.
I wonder how many different ram cards were produced for the A500… the one I had was ICD’s AdRAM 540, which consisted of the main board in the trapdoor bay, a small board that fit beneath the Gary IC, and a small ribbon cable linking the two. The truly nice thing about that card today is the battery backed clock ran on (I think) a CR2032 lithium battery instead of the dreaded NiCd battery.
After you repair a computer what do you do with it return it to donor or keep it or list it for sell? Really enjoy watching your repair videos on the vintage computers. Takes me back to a earlier time .
Naval jelly is basically phosphoric acid and a binder. Bilt Hamber makes the best alternative in Deox-gel. You can make your own using some sort of starch, water, and acid. Phosphoric is particularly nice on steel, because the phosphate it leaves behind is good at holding oil or wax for further protection. Citric acid is common and very mild and benign, leaving clear surfaces. Clean white vinegar is probably the most widespread stuff. Avoid Hydrochloric acid and chlorine like the plague if you care about metals in the room! See also: Parkerizing.
@@jantonkens9820 those people are a minority. In the US we have a glorious system where a minority of a minority can hold the entire government hostage. It's so fucking smart. Thank god our founding fathers knew that they couldn't trust anyone but the aristocracy.
If the keyboard is anything like most keyboards with a membrane sensing mechanism, you should be able to separate the layers of the membrane and clean up whatever gunk is on there and use a conductive silver pen to redraw the traces. That's what those pens are actually designed for! Also useful for membrane flex connections that use that same silver trace material that can wear off. Make sure it's using paint and you let it harden completely. A rather easy fix honestly.
I owned a C64, but never got an A500 as a teen. Still hoping for an A500 Maxi sometime. A MEGA65 would also be great, but the price is too high for me.
I usually just disassemble the keyboard and clean the plungers and the membrane with windex. Quite simple to do and most often solve any keyboard issues.
I remember having a Workbench 1.2 Amiga 500 as a kid. It was also weird in that it could handle 1.44mb HD Floppy disks, I'm pretty certain they were only supposed to be able to handle DD disks. I do miss that quirky machine!
early A500 did ship with Kickstart v1.2. I had one. The only real difference was that you could boot from a HDD with v1.3. You could run Workbench 1.3 on the 1.2 rom, in fact there was a patch that would load at boot time that would fix a few bugs in 1.2. As for bootable HDD, it was still possible with custom boot ROMs. I had a GVP expansion box that included its own boot ROM that allowed me to boot from HDD with Kickstart 1.2. (It also had 2MB of fast ram). I later did upgrade the ROM to v1.3 and yes I had to have a tech install the bodge wires for it. I also upgraded it to the ECS Agnus that allowed 1MB of Chip ram (also software PAL/NTSC switching, for those rare instances I ran into PAL games). I was trying to remember if I actually had 1MB of chip ram (the 512k "trap door" cannot be used as chip ram, it's actually called "slow" ram..) but I'm not sure, I think I might have had the 512k ram chips desoldered and 1MB of chips installed on the board. So I had an A500 with 2mb of Fast ram, 1mb of chip ram, and 512k of "slow" ram... and a 30MB I think SCSI HDD. Pretty slick for an 80s kid.. though I would later upgrade to an A3000. That computer also came with a dual rom setup and a menu that let you boot into Kickstart 1.3 -or- 2.0..
New membranes are available but not for the one which uses 2 ribbon cables AFAIK. You can even get a 'pcb' type membrane instead of the original type. It's well worth changing the two larger capacitors near near the power input jack, they're notorious for failing and causing issues when accessing disks.
25:01 "You know what, this has got to be because this thing is running NTSC and I think it's designed for PAL" Hmm, that explains why it says "NTSC Will Fail" directly above it.
Need to point out that when making a video, I can't sit there for 30 seconds and read everything on a screen. That doesn't make particularly compelling or interesting videos......
The membranes on the A600 and A1200 usually fail because of the wear and tear on the flat flex from moving, unplugging and reconnecting the keyboard to the motherboard. Since the A500 keyboard membrane is usually left attached to the integrated controller board it is more robust. A500 keyboards tend to be older than A600 or A1200 ones and the individual switches are a more likely point of failure through loss of conductivity. Repair should be possible with cleaning/conductive paint or replacing the key plunger with a spare from a broken keyboard.
A non-working key can be either a result of a faulty membraine (one path rotten - can be fixed with a conductive paint) but it also may be due to oxidation of a plunger - you won't know it untill you disassemble it.
Hello from Portland! I am currently working on my 500 rev 5. Hunting down a 1Meg Agnes and seemed to have lost the screws for the keyboard (replaced the membrane a couple of years ago) and the case.
Ok yeah I recall the manual for the 1084 (mono) saying to use a RCA combiner to make it mono. Nice improvement they did it right on the motherboard on the later machines.
if it's a membrane of rubber domes... then I've done similar, since many game controllers and remotes use similar tech. Typically, the membrane has a graphite patch in the center, which shorts across two exposed copper contacts when the key is depressed. Just like many game controllers. If the membrane itself is intact, but the contact pad is bad, it's just a matter of affixing a suitably conductive substance to the contact patch. I've done it only on NES controllers, calculators, and a TV remote -- short term, graphite worked, but needed redoing. Aluminum foil did not work - -the oxide layer isn't great. Copper detailing foil did work. (Scaring me to think that was 30 years ago.)
Re: Keyboard. With the Mitsumi keyboards it's often not the membrane that's the problem. Instead it's the carbon impregnated rubber on the bottom of the stems. This will often oxidise and become non-conductive if left in a damp environment. You can buy carbon paint, often sold for garage door remote button and remote control button fixing to get them working again.
Yeah sounds like it's similar to the Mitsumi plunger style keyboard used the PET and C64. I have strategies for refurbishing those like the paint -- so I'll need to try it on this.
Oh interesting. I did try it on another A500 and there were no issues ... so I assume it's something on this machine. Perhaps it's a design issue on the Rev -5 board.
I had a Rev5 Amiga, and when I replaced the Kickstart ROM with 1.3 It did not require any bodgewire for my system. The only issue it seemed to have was a serious problem with my 3rd party bootstrap ROM for my 20MB HDD, it would hang for up to a minute on a gray screen before booting from the HD. I ended up just booting Workbench from floppy and using the HD as storage until I sold the whole thing to help finance my first PC in 1992.
Any time Adrian is about to put something in a socket that's suspect, I always say "DEOXIT THAT SOCKET!" and pray he says the words. They're the magic words, if you don't say it, the computer never works guaranteed.
You could try some method of cold soldering, aka condutcive glue, to fix membrane if trace went bad, but it could be just dirty. Only way to find out is disassemble it and take good look, im affraid.
Yeah the rains are getting more and more intense. Here in NC we've started having more thunderstorms in the winter which is weird. IIRC we've always had them but not as frequently or as heavy.
If the membrane is dirty just split it apart at the F1 and Esc keys and clean the contacts with a pencil eraser first. If that doesn't work try a tiny bit of the carbon conductive paint. I actually used aquadag paint myself, I didn't want to spend the money for the membrane paint.
I have seen some people having minor success using a conductive ink pen to repair connections on those type of membranes used in the keyboard, can't guarantee anything but it could be worth a shot.
I used silver conductive paint too on my rev5 keyboard years ago to repair some traces. I remember detecting them by looking to the membrane in front of a lamp, then you see clearly the gaps on some traces. I have tried a chinese copper conductive pen but didn't work for me, only my old silver paint did the job.
I wonder if you should keep one of your low cost oscilloscopes connected to a video cable, for better "sign of life" testing than various video digitizers.
a total stranger to cellars I would like to learn more about the sump pump. Is it catastrophic if it fails while raining for days. And havent seen rain for ages so would like to see that too
I don't think so -- the house would have never had one for almost the entire life of the house (it's over 100 years old) but it just means you might have a little water from time to time. I have a triple sump with redundancy including battery backup, so it's much less likely to have a problem than a single pump which most people have. The sump pumps just sit in a big hole that is deeper than the concrete floor. so any water will collect there first and it gets pumped out and into the garden.
I had an Amiga 500 a couple of years ago where some important key was not working and it had a plunger type thing that I moved over from a less important key. I don't know what type of keyboard that was, cleaning didn't help with those plungers.
Definitely go with replacing the keyboard membrane, once you start chasing issues with them things, they just create more problems, var easier in the long term to just swap it out and have a nice working keyboard... :)
Having a double size ROM with the largest address pin floating isn't much of a problem if you just write the ROM binary in there twice so that both halves of the memory have the same content.
Heh. I need my boost so have a Forester XT. :-) A friend of mine who's also into retro stuff did just buy an Element SC though. He's really excited about the hauling potential
Because you had Kickstart 1.2 it would had been interesting to see the label underneath. Most likely a 1987 model. I bought mine 1988 and am pretty sure had Kickstart 1.3 right away. For Test Drive. Yeah, HP of Porsche, Ferrari and others are ridiculous today. But prices too. Don't think you get a new 911 for 50K these days. Also the game was made in Vancouver! Yay Canada! I think I had it back in the day, but never noticed it was made in British Columbia.
Although I think 50k back then is worth about $122k now -- so that seems a bit more comparable? And considering a Porsche back then had basically no technology -- it's rather surprising really! As for the year, I don't recall seeing any dates on that machine -- I have never come across a motherboard that didn't support 512k ROMs.
@@adriansdigitalbasement2 I liked cars back in the day when they were cars. Today they are computers on wheels. Thus I don't mind prices of Porsches or Ferraris today as I'd never buy one. For the date I also tried to stop the video when you showed to board, but never could see any. There seems also no mention of the year on the label at the bottom. Btw. a (rich) friend bought an Amiga 1000 in early 1986. While paying an arm and a leg, it ran Kickstart 1.1. First time I used a mouse when I came for a visit. Greetings from your birth town at -27 C.
Every time I see you waving your hands on camera when the rest of you isn't in the shot reminds me of the end of Svengooile when all you see the waving hands of the guy at the door telling bad jokes
It's important to remember that S-Video is *not* the same as the Y/C input on the monitor you're using. It operates at a lower voltage on the chroma pin. To bring it up to standard for your 1702/1084 you'd need a small amplifier on the chroma circuit.
It may be slightly different voltage but it seems like the analog circuits are super forgiving. I've certainly never had any issues with the color decoding circuit on that monitor when used with modern S-Video devices. I think the reason is the color decoded uses the amplitude of the colorburst as a reference -- so the higher or lower voltage the whole chrome signal is doesn't have much of an affect as the relative change is the same between the color information and the color burst.
LOL, the Lotus weighs about 1,300 pounds less than (65% of) your Subaru Forester XT. Colin Chapman (founder of Lotus) philosophy: "Adding power makes you faster on the straights. Subtracting weight makes you faster everywhere." Just sayin'. ;-)
Some Amiga shops (Sordan Electronics I know for sure) sell ready-made adapters for using EEPROMs in the Rev. 5 Amiga boards. Although the A500 I got off eBay a few years ago was upgraded to Workbench 2.04 but they had to tie some of the legs of the ROM together with thin wire to get it working in the Rev. 5.
With engine HP you have to look at the rpm. Small capacity Euro engines make peak power at high rpm, ie, they feel dead until rev-ed, where as a big cu V8 will feel better with the same HP because that power is at a lower rpm, ie, more grunty. This was a while back so the exact numbers are a bit foggy, but as an extreme engine an Amsoil Engine Masters Challenge engine(V8 400cu) will make about 700hp@6500, and something like 200hp@2500 - more than most cars flat-out lol -.
I'm guessing it was stored vertically with the left side down, so any/all water(?) corroded that connector and plating parts. Possibly also the ESC and F1 key issues?
Oh yeah it's on the same side as the corrosion ... strange is this machine was inside a box and packing foam, and the box is in OK shape. So I don't really get where the corrosion came from.
Yeah if the trace is bad once I remove the solder mask, I'll use metal like component off-cuts to restore the trace. Or, if it's longer distance like for the ROM mod, I use wire-wrap conductor to do it.
@@adriansdigitalbasement2 oh on a pcb, certainly, that's easy :-). I meant in the plastic membranes in keyboards and keypads. The best luck I had was with some foil and superglue.. It lasted 5 minutes :-)
I am a bit confused.... In have always believed that the A500 had an RGB port built in and connected directly to a 1084 monitor, with color. My wife had both when we met and we played tons of great games on it. But it sounded like Adrian said that the A500 was monochrome without the adapter that he was using here. Edit: yes. He said that both the 500 and 2000 only had monochrome as native output. But I feel pretty sure that this is not true. Anybiy else able to confirm?
![Adrian's Digital Basement ][](http://yt3.ggpht.com/ytc/AIdro_k7CrQRe71qN6c0Ua7A1P_I8KkxjqLa70u0zYeCvdvnKw=s48-c-k-c0x00ffffff-no-rj)
A lot of the amiga stores sell new membranes as well as a more sturdy replacement. They also sell a rom fix that just plugs into the rom socket for anything above 1.3
Yeah I bought one from ebay from a guy in Poland worked perfect when my space just stopped working.
I see they make a PCB replacement for the membrane -- that's cool
Heck yeah it’s sweet
Plus membranes can be fixed with those magic silver pens (that's actually what they're designed for).
@@SockyNoobyeah i have done that before.
It can work but its a bit sketchy
As started Adrian, When I was in my teens (early 2000's), I had an old membrane keyboard from my parents compaq presario 5000t. One day a whole group of keys stopped working. I was able to disassemble the keyboard and using a multimeter I found where the trace had broken apart. (unsure what caused it). Soldering was out of the question on the thin plastic membrane, BUT I used some rear window heater grid paint available from auto parts stores. Comes in a real small bottle with a paintbrush. Painted a few coats over the split and reassembled the keyboard. Worked like a charm.
This is definitely the way I would recommend unless it is a dual layer film membrane (sometimes with a third separating layer). Separating the layers can destroy them sometimes depending on how it is made. Single layer membranes can usually be fixed as long as the ribbon cable connector is still good. How long it will last is hard to say, but usually quite a while. Conductive paint is pretty awesome. Needless to say, be careful when doing this because that stuff can make a terrible mess on a board and it is conductive.
Please take your time, Adrian. 2 videos per week is a lot and if you skip one, now and then, noone will be angry. There is no need to ever rush things.
It's nice to see a piece of ITALIAN software running on an American Amiga. :)
Logica was an Italian company which produced accessories for the Commodore Amiga line of computers. Amiga had a huge success in Italy back in the day.
I repaired my A500 keyboard with silver contact paint. It's about as expensive as printer ink, but does the job fixing hairline cracks in flatflex stuff if it is under low mechanical stress. So once the membrane is inside the sandwich again, it should be fine. Hint though: let the paint dry, it will not conduct properly when still wet. :) (edit: I still haven't edited the video for that one; it's my oldest "eventually" spare content one but on mine one of the Amiga keys was dead, and you need both for the reset combo)
I had the same problem, and come up with same solution - works great! Done it about 7-8 years ago, and it still works flawlessly!
I came here to say conductive ink pen should fix it. The paint is probably more robust.
Fun fact: That's actually what conductive silver pens are designed for! Repairing membrane traces that can be worn off over time.
Adrian needs more iFixit sponsorships, I always enjoy his videos.
Greetings to you Adrian from your neighbour to the north in BC.
Naval Jelly is nothing short of AMAZING! There’s ALWAYS some in my house!
I had never heard of it until viewers told me about it. It's not my go-to stuff to help rid battery leak corrosion from boards.
Adrian is at his best when tinkering with an Amiga!!!
The only way I know of to fix one of the A500 membrane keyboards is to seperate the layers and clean the contacts with a pencil eraser. It's risky but does work very well in most cases. If you find carbon pads benieth the keys I would use isopropanol and a cue-tip or other cotton swab. For the carbon pad on the key side, just rub it acros some paper until it leaves a good solid skidmark that is the same width as the pad. Note that this trick also works for TV remotes where keys stop working.
This was my first computer!! So cool
Back in the day I used a RGB to Scart connector on my Sony CRT. Looked way better then my 1084s monitor!
Hi, When you showed use the clean motherboard. It looked like new, good job.
I have repaired membrane keyboards with a conductive paint, intended for repair of rear window defroster in cars. It works great.
works better for repairing keyboards than using it to repair the defroster
@@mauzzz2418 well I got it to work for defroster somewhat okay, had to paint in several layers, letting it dry in between.
To repair Atari membrane keyboards I've used silver conductive paint, for durability I've added a little superglue on top of the silver conductive paint.
Yeah I used a silver pen on keyboards before with success.
Very interesting video glad u managed to get it working well 🙏
Well this video answers a 30 year old mystery of when a computer store I took my Rev5 Amiga 500 could never get it to run a Kickstart 2.0 rom
Funny too is there is no easy to find answer to this problem even today -- knowledge is there but Google search results give mixed and unclear results.
It shows that it is important to write in a clear way and make sure the information is correctly presented.
I really could have done with something like that S-Video adapter back in the day. That combo of the 1702 and the A500 (rev5) was my setup. I used the colour composite out of the A520 modulator. Which was ok but slightly blurrier than I would have liked.
Indeed -- the S-Video was shockingly nice compared to the composite video. It certainly work but it means the high res text is a bit hard to read.
I’ve repaired a few amiga keyboards. Yes there are a few options for membrane replacements. The one I favour is the “hard” membrane replacements, readily available in the UK, sadly I’m not sure of availability in the US.
But I’d try fixing first. Having removed the 40million screws (slightly larger screws around the pcb controller to watch for), remove the membrane, place on flat surface and gently wipe with water or if feeling brave some glass cleaner can work well.
Sometimes I’ve needed to refurbish the little plunger, some conductive
paint can be used (Liquiwire
50mL Electrically conductive paint for PCB & electric circuit repair from Amazon) is what I’ve used with success, dip the plunger into it and let dry. As you say Esc and F1 not working when the rest work usually points to plunger or dirt on membrane. Before going to the bother of getting the conductive paint, try swapping a couple of plungers around.
Hope this helps.
Always good value. Keyboard Membrane Repair, FWVLIW:
Just don't, you'll be much happier!
...but if you must, or just don't have an option: (nobody makes replacement membranes for my favourite retro system)
1) Find the schematic and test the leys.
This will likely tell you if the issue(s) is/are with:
-The connection with the with the computer (I hope you checked that first!)
-The controller or it's connections (hopefully the socket or dry solder joints, not the chip itself)
-One (or more) of the main row/column traces on the membrane (repairs are easier if any cracks aren't near the keys)
-An individual key or local trace(s)
2) Carefully disassemble the keyboard:
-Dry clean the key mechanisms and partially reassemble. If you're very lucky it was just guck / grit
-Brush down the outsides of the membrane ONLY and give it a gentle flap. Test again, maybe just a bit of grit / guck
-Being VERY CAREFUL look for any cracks in the FULL LENGTH of likely tracks by continuity testing and then magnification to find the exact spot(s)
-No clue? AMAZINGLY CAREFULLY push a FLATTENED cotton bud tip between the membranes where the key presses and GENTLY rub both sides
(It may be the pads have a bit of build-up that is preventing conduction, hopefully you shifted it without scrubbing off the usually very delicate film)
-If you found a cracked trace you can effect a repair with a product like Wire Glue, Silver contact paint, or similar...
a) It's amazingly important NOT to daub it on - claggy lumps ruin membranes. Whisker-thin dab, dry, test, more if necessary...
b) If the crack(s) is anywhere near a key actuation spot you are almost certainly NOT going to effect a successful repair, but try if you must.
Second last resort:
If it really looks like all the traces are good, it's just that the pads under the key(s) are worn out you may get away with the old drawing on the pads with a soft led pencil trick, taking care NOT to distort or scratch the plastic. If this works at all it probably won't last long. Alternately a very VERY thin layer of Wire Glue or similar might help. You can even try applying a small circle of gold leaf!!! (expensive, horribly fiddly)
Last (first?) resort:
You could design your own replacement keyboard PCB to interface with the old logic. Not as hard as you might think - there are online resources to help. Two options:
a) A PCB with SMT tact-switches or dome switches to go where to old membrane lived. If there's room, great. If not you may need to sand a little off the bottoms of the old key plungers - this will leave you with a seemingly authentic keyboard that's more reliable and a better action. Best to order a PCB thinner than the standard 1.6mm if you can, some manufacturers will even do flexible ones but they are horribly expensive and they aren't necessary. An awesome mod for the old rubber-key ZX Spectrum, but it works for many mechanical keyboards too. The old membrane will serve as a template for your layout.
b) A complete new mechanism using modern mechanical switches - more fashionable and possibly more robust and future-proof. But modding old keycaps to fit new switches is a bugger, as is finding new keycaps that look the part. Then there's the whole "Am I going to have to design / program my own controller too?"
I hope that helps someone.
Nice to see we are both members of the 1702 with a front cover club! :)
Heh yeah I'm lucky to have a nice specimen with an in-tact door! I treat it very gingerly.
wow man. that looks like it was frustrating as shit. props for sticking with it
On the flickering video check the two large caps near the video port. They tend to go bad and can short out. They will also over heat the resistors. I've had that occur on two of my version five boards
Look for broken traces on the keyboard membrane. Use conductive epoxy if you find any.
I fixed a membrane Sun keyboard with a trace repair pen.
Also, the older kickstart roms are a different size. There’s an adapter to allow larger roms.
Thank you Adrian! I just got request to fix A500. So that might be helpful.
One thing I am going to miss about living in Portland is the rain.
When the screen hits your cam, like a big swirly spam, that's a moiré
We've had rain for most of a week here in Texas, but no basements! The ground is wrong on one way or another for basements, but here it's limestone like a foot or two below the ground.
Great fixes. Another Amiga saved... well, mostly. I bet your Subaru doesn't corner as well as the Lotus Esprit. 😉
Don't need those two keys for Lemmings so... win win!
Nice video as usual - I'm disappointed you didn't use the dremel on those torx screws :)
If I remember correctly those mitsumi keyboard membranes are actually single layer and there are rubber plungers which make a connection between 2 pads to register the keypress (in the same way as the c64 keyboard works). I'd be tempted to take the keyboard apart and check that the issue isn't simply that the rubber contacts on the bottom of the plungers are dirty for those two keys and hence are not making a good connection or that there isn't just a bit of fluff in there thats preventing those keys from making a good connection.
Ah I see -- so instead of a PCB like on the C64 they just put the carbon contacts on a membrane?
@@adriansdigitalbasement2 I think the samsung ones might be two layer, but yeah, I'm pretty sure the mitsumi ones are just contacts on a membrane. I'm guessing it saved commodore a few pennies. There are now aftermarket solutions where you can replace the membrane with a proper pcb solution instead. I've never tried those, so don't know whether its an upgrade or not though.
This exactly. Don't discount the rubber on the posts. I was given (5) A500 keyboards to repair and only one had a bad membrane but the rest had various keys that did not work and in all of those cases it was the rubber that lost its conductivity. Replacing them fixed all of them. If it does turn out to be the membrane you can purchase new replacements including a PCB version that uses a very thin PCB and gold contacts. I have used both solutions and they both work great.
I wonder how many different ram cards were produced for the A500… the one I had was ICD’s AdRAM 540, which consisted of the main board in the trapdoor bay, a small board that fit beneath the Gary IC, and a small ribbon cable linking the two. The truly nice thing about that card today is the battery backed clock ran on (I think) a CR2032 lithium battery instead of the dreaded NiCd battery.
After you repair a computer what do you do with it return it to donor or keep it or list it for sell? Really enjoy watching your repair videos on the vintage computers. Takes me back to a earlier time .
Naval jelly is basically phosphoric acid and a binder. Bilt Hamber makes the best alternative in Deox-gel. You can make your own using some sort of starch, water, and acid. Phosphoric is particularly nice on steel, because the phosphate it leaves behind is good at holding oil or wax for further protection. Citric acid is common and very mild and benign, leaving clear surfaces. Clean white vinegar is probably the most widespread stuff. Avoid Hydrochloric acid and chlorine like the plague if you care about metals in the room! See also: Parkerizing.
Rainy December?? We are in February!!
Alternate date keeping.... In the USA people do like alternate facts and maybe now also alternate dates 🤔😂🏳️🌈🏳️🌈🦆
Also it's only just February 😜
@@jantonkens9820 those people are a minority. In the US we have a glorious system where a minority of a minority can hold the entire government hostage. It's so fucking smart. Thank god our founding fathers knew that they couldn't trust anyone but the aristocracy.
He’s from the future
@@michaeldonoghue9015 Working on retro stuff before it's even retro
4:45 "Inside the computer's a bit of a musty odor so, this thing was obviously stored...outside..." LOL!
You had some bad luck with that revision 5 A500, A500 normally in good condition, except for Rev 8's, nice job!
If the keyboard is anything like most keyboards with a membrane sensing mechanism, you should be able to separate the layers of the membrane and clean up whatever gunk is on there and use a conductive silver pen to redraw the traces. That's what those pens are actually designed for! Also useful for membrane flex connections that use that same silver trace material that can wear off. Make sure it's using paint and you let it harden completely. A rather easy fix honestly.
I owned a C64, but never got an A500 as a teen. Still hoping for an A500 Maxi sometime. A MEGA65 would also be great, but the price is too high for me.
Cool !! Hello from Brazil !
The day was going straight into the toilet... but now, this video marks the day's turnaround! Heh
What you call "Workbench" in the beginning is actually called "Kickstart" :-)
Navy Jelly I was thinking belly button jelly LOL!
Naval jelly is phosphoric acid with a gelling agent.
Notification Squad! :D
I like the hard membrane replacementa
I usually just disassemble the keyboard and clean the plungers and the membrane with windex. Quite simple to do and most often solve any keyboard issues.
I remember having a Workbench 1.2 Amiga 500 as a kid. It was also weird in that it could handle 1.44mb HD Floppy disks, I'm pretty certain they were only supposed to be able to handle DD disks. I do miss that quirky machine!
Probably only 720kb?
early A500 did ship with Kickstart v1.2. I had one. The only real difference was that you could boot from a HDD with v1.3. You could run Workbench 1.3 on the 1.2 rom, in fact there was a patch that would load at boot time that would fix a few bugs in 1.2. As for bootable HDD, it was still possible with custom boot ROMs. I had a GVP expansion box that included its own boot ROM that allowed me to boot from HDD with Kickstart 1.2. (It also had 2MB of fast ram). I later did upgrade the ROM to v1.3 and yes I had to have a tech install the bodge wires for it. I also upgraded it to the ECS Agnus that allowed 1MB of Chip ram (also software PAL/NTSC switching, for those rare instances I ran into PAL games). I was trying to remember if I actually had 1MB of chip ram (the 512k "trap door" cannot be used as chip ram, it's actually called "slow" ram..) but I'm not sure, I think I might have had the 512k ram chips desoldered and 1MB of chips installed on the board. So I had an A500 with 2mb of Fast ram, 1mb of chip ram, and 512k of "slow" ram... and a 30MB I think SCSI HDD. Pretty slick for an 80s kid.. though I would later upgrade to an A3000. That computer also came with a dual rom setup and a menu that let you boot into Kickstart 1.3 -or- 2.0..
@@VIC-20 880k
Hi Adrian. There's something in the UK called JENOLITE Rust Remover Thick Liquid. Not used it myself, but it looks pretty similar to Naval Jelly.
Awesome -- that's good to know. I get asked from folks overseas what they can use that works in a similar way.
New membranes are available but not for the one which uses 2 ribbon cables AFAIK.
You can even get a 'pcb' type membrane instead of the original type.
It's well worth changing the two larger capacitors near near the power input jack, they're notorious for failing and causing issues when accessing disks.
Yeah I bet those caps are problematic -- it makes the most sense.
25:01 "You know what, this has got to be because this thing is running NTSC and I think it's designed for PAL" Hmm, that explains why it says "NTSC Will Fail" directly above it.
Need to point out that when making a video, I can't sit there for 30 seconds and read everything on a screen. That doesn't make particularly compelling or interesting videos......
Naval Jelly will attack paint and galvanized metal...so use with care. I've used it a lot for car stuff.
The membranes on the A600 and A1200 usually fail because of the wear and tear on the flat flex from moving, unplugging and reconnecting the keyboard to the motherboard. Since the A500 keyboard membrane is usually left attached to the integrated controller board it is more robust. A500 keyboards tend to be older than A600 or A1200 ones and the individual switches are a more likely point of failure through loss of conductivity. Repair should be possible with cleaning/conductive paint or replacing the key plunger with a spare from a broken keyboard.
A non-working key can be either a result of a faulty membraine (one path rotten - can be fixed with a conductive paint) but it also may be due to oxidation of a plunger - you won't know it untill you disassemble it.
Hello from Portland! I am currently working on my 500 rev 5. Hunting down a 1Meg Agnes and seemed to have lost the screws for the keyboard (replaced the membrane a couple of years ago) and the case.
About audio, only from A1200/600 you have mono sum on the RCA. Original models 1000-500-2000 are stereo only
Ok yeah I recall the manual for the 1084 (mono) saying to use a RCA combiner to make it mono. Nice improvement they did it right on the motherboard on the later machines.
if it's a membrane of rubber domes... then I've done similar, since many game controllers and remotes use similar tech.
Typically, the membrane has a graphite patch in the center, which shorts across two exposed copper contacts when the key is depressed. Just like many game controllers.
If the membrane itself is intact, but the contact pad is bad, it's just a matter of affixing a suitably conductive substance to the contact patch. I've done it only on NES controllers, calculators, and a TV remote -- short term, graphite worked, but needed redoing.
Aluminum foil did not work - -the oxide layer isn't great.
Copper detailing foil did work. (Scaring me to think that was 30 years ago.)
Re: Keyboard. With the Mitsumi keyboards it's often not the membrane that's the problem. Instead it's the carbon impregnated rubber on the bottom of the stems. This will often oxidise and become non-conductive if left in a damp environment. You can buy carbon paint, often sold for garage door remote button and remote control button fixing to get them working again.
Yeah sounds like it's similar to the Mitsumi plunger style keyboard used the PET and C64. I have strategies for refurbishing those like the paint -- so I'll need to try it on this.
I had the same VIP video adapter and I too saw the interference when accessing the floppy drive, although to a lesser degree.
Oh interesting. I did try it on another A500 and there were no issues ... so I assume it's something on this machine. Perhaps it's a design issue on the Rev -5 board.
The last A500 I tried it with was a Rev 6a. It is entirely possible it needed some caps replaced.
I had a Rev5 Amiga, and when I replaced the Kickstart ROM with 1.3 It did not require any bodgewire for my system. The only issue it seemed to have was a serious problem with my 3rd party bootstrap ROM for my 20MB HDD, it would hang for up to a minute on a gray screen before booting from the HD. I ended up just booting Workbench from floppy and using the HD as storage until I sold the whole thing to help finance my first PC in 1992.
The issue is 512k roms like 2.0 and higher as well as using eeproms on rev 5 boards.
Right ok -- couldn't recall is 1.3 was 512k or not -- so yeah any 256k ROM would be fine on that system.
@@adriansdigitalbasement2 1.3 was just 1.2 with bug fixes like working autoboot from hd.
Any time Adrian is about to put something in a socket that's suspect, I always say "DEOXIT THAT SOCKET!" and pray he says the words. They're the magic words, if you don't say it, the computer never works guaranteed.
There exist a silver, that can be used on these membranes, to recreate the circuits on these membranes. So the contact will be as new.
You could try some method of cold soldering, aka condutcive glue, to fix membrane if trace went bad, but it could be just dirty.
Only way to find out is disassemble it and take good look, im affraid.
Yeah the rains are getting more and more intense. Here in NC we've started having more thunderstorms in the winter which is weird. IIRC we've always had them but not as frequently or as heavy.
If the membrane is dirty just split it apart at the F1 and Esc keys and clean the contacts with a pencil eraser first. If that doesn't work try a tiny bit of the carbon conductive paint. I actually used aquadag paint myself, I didn't want to spend the money for the membrane paint.
I have seen some people having minor success using a conductive ink pen to repair connections on those type of membranes used in the keyboard, can't guarantee anything but it could be worth a shot.
I used silver conductive paint too on my rev5 keyboard years ago to repair some traces. I remember detecting them by looking to the membrane in front of a lamp, then you see clearly the gaps on some traces. I have tried a chinese copper conductive pen but didn't work for me, only my old silver paint did the job.
I cry for the Amiga
There are membranes available. I still have one laying around.
Let me know if you need one.
Thank many people have left comments on how to take it apart and clean it -- so I'll try that first
Great video Adrian! Have you ever used that CLR Calcium, Lime, & Rust Remover stuff to clean contacts on any vintage computer?
I've only used it in my bathroom. I would worry it's too harsh on the non corroded metal parts of the machine.
@@adriansdigitalbasement2 Gotcha.
I wonder if you should keep one of your low cost oscilloscopes connected to a video cable, for better "sign of life" testing than various video digitizers.
a total stranger to cellars I would like to learn more about the sump pump. Is it catastrophic if it fails while raining for days. And havent seen rain for ages so would like to see that too
I don't think so -- the house would have never had one for almost the entire life of the house (it's over 100 years old) but it just means you might have a little water from time to time. I have a triple sump with redundancy including battery backup, so it's much less likely to have a problem than a single pump which most people have. The sump pumps just sit in a big hole that is deeper than the concrete floor. so any water will collect there first and it gets pumped out and into the garden.
@@adriansdigitalbasement2 interesting, so it seems the addition of the sump pump is extra measrues to keep things extra dry
So there was orange juice spilled on the ESC/F1 region and ran all the way down the CPU connector to the green and rusted screws🧐
Would certainly explain things -- there was no evidence of crusty dried juice but who knows. Maybe someone cleaned that up a bit.
I had an Amiga 500 a couple of years ago where some important key was not working and it had a plunger type thing that I moved over from a less important key. I don't know what type of keyboard that was, cleaning didn't help with those plungers.
Definitely go with replacing the keyboard membrane, once you start chasing issues with them things, they just create more problems, var easier in the long term to just swap it out and have a nice working keyboard... :)
Having a double size ROM with the largest address pin floating isn't much of a problem if you just write the ROM binary in there twice so that both halves of the memory have the same content.
Not sure how it is with ROMs, but with microcontrollers, leaving an input pin floating can lead to excessive current consumption.
Yeah would work OK if you're using a small ROM image. Can just add a pull up resistor to the pin easily enough too.
Of course you drive a Forester and live in Portland what else could it be. Just remember the cool kids drive vintage Elements.
Heh. I need my boost so have a Forester XT. :-) A friend of mine who's also into retro stuff did just buy an Element SC though. He's really excited about the hauling potential
Because you had Kickstart 1.2 it would had been interesting to see the label underneath. Most likely a 1987 model. I bought mine 1988 and am pretty sure had Kickstart 1.3 right away.
For Test Drive. Yeah, HP of Porsche, Ferrari and others are ridiculous today. But prices too. Don't think you get a new 911 for 50K these days.
Also the game was made in Vancouver! Yay Canada! I think I had it back in the day, but never noticed it was made in British Columbia.
Although I think 50k back then is worth about $122k now -- so that seems a bit more comparable? And considering a Porsche back then had basically no technology -- it's rather surprising really! As for the year, I don't recall seeing any dates on that machine -- I have never come across a motherboard that didn't support 512k ROMs.
@@adriansdigitalbasement2 I liked cars back in the day when they were cars. Today they are computers on wheels. Thus I don't mind prices of Porsches or Ferraris today as I'd never buy one.
For the date I also tried to stop the video when you showed to board, but never could see any. There seems also no mention of the year on the label at the bottom.
Btw. a (rich) friend bought an Amiga 1000 in early 1986. While paying an arm and a leg, it ran Kickstart 1.1. First time I used a mouse when I came for a visit.
Greetings from your birth town at -27 C.
Naval jelly is phosphoric acid.
No wonder you have to be careful to fully wash it away!
Every time I see you waving your hands on camera when the rest of you isn't in the shot reminds me of the end of Svengooile when all you see the waving hands of the guy at the door telling bad jokes
If I remember correctly the 1.2 Rom is what the 500 was first released with.My 500 came with the 1.3 Rom no wire was needed.
It's important to remember that S-Video is *not* the same as the Y/C input on the monitor you're using. It operates at a lower voltage on the chroma pin. To bring it up to standard for your 1702/1084 you'd need a small amplifier on the chroma circuit.
It may be slightly different voltage but it seems like the analog circuits are super forgiving. I've certainly never had any issues with the color decoding circuit on that monitor when used with modern S-Video devices. I think the reason is the color decoded uses the amplitude of the colorburst as a reference -- so the higher or lower voltage the whole chrome signal is doesn't have much of an affect as the relative change is the same between the color information and the color burst.
LOL, the Lotus weighs about 1,300 pounds less than (65% of) your Subaru Forester XT.
Colin Chapman (founder of Lotus) philosophy: "Adding power makes you faster on the straights. Subtracting weight makes you faster everywhere." Just sayin'. ;-)
Try the stuff the 8 bit guy used on the contacts of his commodore pet keyboard
Fun fact the mono composite is generated by video hybrid circuit
to fix the keyboard problem, you have to disassemble it and use silver contact paint and repaint the traces.
If you're using the Diag rom, why was there no null modem hooked up to capture the output?
Adrian if i was you i would make an adaptor for the eeprom from a chip socket with the modification on the socket so as not to mess up the diag rom
Some Amiga shops (Sordan Electronics I know for sure) sell ready-made adapters for using EEPROMs in the Rev. 5 Amiga boards. Although the A500 I got off eBay a few years ago was upgraded to Workbench 2.04 but they had to tie some of the legs of the ROM together with thin wire to get it working in the Rev. 5.
With engine HP you have to look at the rpm. Small capacity Euro engines make peak power at high rpm, ie, they feel dead until rev-ed, where as a big cu V8 will feel better with the same HP because that power is at a lower rpm, ie, more grunty.
This was a while back so the exact numbers are a bit foggy, but as an extreme engine an Amsoil Engine Masters Challenge engine(V8 400cu) will make about 700hp@6500, and something like 200hp@2500 - more than most cars flat-out lol -.
I once fixed such a keyboard with some kind of silver paint. No idea what it's called. It's been a few years...
Adrian I can't remember if that model has the audio output reversed caps on the motherboard that need to be changed I think it was all the 500 models.
Please let us have a glimp inside this vip interface :)
At a guess, someone spilt a drink over f1 and ESC then down to the board giving the crusty edge connection.
That is certainly entirely possible. I didn't notice any crusty or dried up stuff - but perhaps it was something that didn't leave much of a trace.
Huh... what are the odds? I own that exact same toolset. It's really handy.
I'm guessing it was stored vertically with the left side down, so any/all water(?) corroded that connector and plating parts. Possibly also the ESC and F1 key issues?
Oh yeah it's on the same side as the corrosion ... strange is this machine was inside a box and packing foam, and the box is in OK shape. So I don't really get where the corrosion came from.
I've tried using all sorts of paint on conductive stuff to fix worn out or broken tracks, but I have never had it work and just given up.
Yeah if the trace is bad once I remove the solder mask, I'll use metal like component off-cuts to restore the trace. Or, if it's longer distance like for the ROM mod, I use wire-wrap conductor to do it.
@@adriansdigitalbasement2 oh on a pcb, certainly, that's easy :-). I meant in the plastic membranes in keyboards and keypads. The best luck I had was with some foil and superglue.. It lasted 5 minutes :-)
It's only one of the audio outputs that gives a combined signal. (I think it's the left channel.)
Some viewers mentioned it's only on the A600 and A1200 that this work -- 500/200 it's not combined on the motherboard at all.
@@adriansdigitalbasement2 Oh. It's a feature of the A500+ that I have. (?)
I am a bit confused.... In have always believed that the A500 had an RGB port built in and connected directly to a 1084 monitor, with color.
My wife had both when we met and we played tons of great games on it. But it sounded like Adrian said that the A500 was monochrome without the adapter that he was using here.
Edit: yes. He said that both the 500 and 2000 only had monochrome as native output. But I feel pretty sure that this is not true. Anybiy else able to confirm?
Does this model have ray tracing?