Wow, I would have known into full paranoid mode. I'd check the ISA slot, the motherboard traces and who knows what before considering the possibility that it was just a coincidence that two cards blew the same cap one after another.
Just bumped on your channel, and wow! There are several good retro PC hardware channels out there, but yours is the only one who explains this stuff properly how these things work electrically. In the end, circuits are simple, but you actually show how troubleshooting and fixing these should be done. Thumbs up!
Some years ago I found a motherboard with a 286 thrown in an old building that was being demolished, and I was lucky that it is working perfectly. Now I think I can make it work when I buy some pieces and have it in my small collection, excellent video
Yeah 286 is also a really nice platform. They are speed devils compared to those xt machines :) and you can get away with using standard 16 bit cards that are easier to find.
Excellent plan. They are very convenient. I use them also but only to bootstrap the pc’s and install some drivers as I setup the machines. I don’t like the look of a gotek in such an old machine. I am also planning to network all of my retro pc’s. have dozens of nics and have setup a nas with all of my retro stuff... that way I can easily hook them up to the network and copy stuff over. Just a matter of inserting a nic and configuring it for msdos or windows.
Still looking for part 3...... Also, where a HDD has a defect list. there will be bad sectors and "attempting to recover allocation unit ...". The defect mapping in low level format marks the track as explicitly bad, so the high level format will have to mark it bad, rather than relying on the high level format detecting them and maybe missing them if they are not "bad enough"
thanks ... check out some of my other videos ... lots more where that came from. And if you like you can subscribe / like / share ... to help support the channel ...
I remember buying a dual processor p200 at a computer store back a few years. Guy gave me a similar machine with it for parts. It was a disaster. It took ages to figure out what was going on and getting it to work. I learned a lot in the process, but from then I always named the box "Disaster". I do miss that machine. I have absolutely zero need for it but it was a lot of fun learning about threaded coding.
All PC Floppies (with a few execptions of course like on the A2088) are configured as B: (DS1). The twist in the cable is what makes them A:, by swapping DS0 and DS1 signals and the Motor Enable Signal. Most floppies are hardwired to be DS1 bute some have the jumpers exposed.
Another nice video. Well done. Re 3.5" FDD. Where as with most IDE drives the red-striped pin one is generally always towards the power connector, 3.5" FDD's ..all bets are off. I've even one baffling one where it has a knotch in the PCB (but not a keyed connector) to allow for a ribbon cable knotch .. and it goes the other way around. Also some drives when you get them the other way around, if there's a bootable disk in there when it lights up, it'll scramble it. Again, well done and looking forward to more of your videos. Great they're a little technical.
Great work on restoring this thing so far. The only thing I have not seen repaired that i noticed in the first part was the leaking Varta battery for the CMOS. It didn't look like it had destroyed anything yet but there was definite signs of corrosion setting in. I would make sure to remove that and clean up the board before it eats away any traces. If you are looking for a good battery replacement, the 3.6v NiCad packs that cordless phones use work well for these old boards.
A 1/4 watt load resistor should make any of these old at’s start. You can put it on any rail I would do a 5v load. Back in the day 30 years ago you could buy a load pack or dummy load device. These were awesome bench power supplies
Ah, tantalum caps, the scourge of old PCs... ;) Regarding the hard drive: I don't think a low-level format would help with the bad sectors. Remember the drive defects on the sticker? Back then, it was totally normal for hard drives to have factory defects. In my opinion it's better to have more sectors marked bad than to constantly get data errors because of data getting stored on defective areas. As long as the bad sectors don't get more, the drive is totally fine ;) Anyhow, congratulations! That's a really nice PC.
I have read somewhere that performing a LLF could get rid of bad sectors, but we need to do a more detailed study on that. (Under what specific conditions).
@@RetroSpector78 That does work indeed, but only with modern drives which have defect management. Modern drives have spare blocks which the drive transparently uses to replace bad blocks. That's why modern drives appear to be defect-free until the spare blocks are all used up. "Low-level-formatting" these drives with the manufacturer's software reorders the blocks so the drive appears to be okay again.
@@kpanic23 modern drives or any IDE drive cannot be low level formatted...old stepper drives loose head and stepper alignment with time...much like floppy drives....LLF rewrites the track and sector structure so the misalignment is no longer a problem...it can make a huge difference in drive reliability, often getting rid of some bad sectors....also erasing wirting and reerasing constantly the same sectro (some software does that) can help revive the magnetic media....if the bad sector is a scratch or a speck of dust stuck to the drive then there is no possible remedy
@@RetroSpector78 Absoluut. Ik ga rustig alles eens bekijken! Ben zelf ook een liefhebber van oude computers, maar dan wel van het socket 7 tijdperk. Ik vraag mij dan ook af of je niet eens onderdelen bij mij gekocht hebt. Ik heb destijds veel onderdelen, die ik niet meer gebruikte verkocht middels MP.
I'd swap all the caps on the cards where one failed, they were probably made in the same chain, have the same age and have lived with the same conditions, so it's only a matter of time before the other caps do this as well. By the way, have you been to Lille (Risjel) last week-end ? there was the big annual flea market in the whole city, and there was some pretty cool stuff to catch there ^^
No I haven't ... never been to these kind of markets actually ... Should get out more :) Here we don't have thrift stores, and the only way to get good stuff is either online, or by word of mouth...
I'd be worried that the -12v rail is putting out a positive voltage. Tantrums very often explode when reverse biased. Did you check the -12v rail? It's normally provided by a LM7912 negative linear regulator and those fail short (which could give you a positive voltage in some cases). The RS232 cards use -12v to provide the mark voltage.
Hi, I have a RGB graphics card with the same problem, one of the tantulum capacitors has exploded. The bad capacitor is connected to rail +12v and i would like to know what are the specs i have to look for to buy a new one. I can only read 106F on it. Also, it would be great to have some info about this very large graphic card, i couldnt find any brand name on the PCB, only CGP-880 and it was made in taiwan. Thanks
Is that a loose screw sticking to the underside of the floppy drive at 1:47? I see it again at 3:05... still watching, waiting to see if he notices it...
Angela Walker spoiler alert : he didn’t ? :) But I do vaguely recall a situation with a missing screw and a diskdrive. But not 100% sure if it was with this one :)
I remember having an old scsi hard drive with bad sectors, I used scandisk on it over and over until it had a clean slate... It shrunk from 105mb to about 90.... :( This was the first drive I ever had in my 386 when I was a kid in about 1993 or so.
You won't be visiting any flashy new websites soon on this thing :) But you can get it connected to the internet using tcp/ip that's for sure. But your internet experience will be limited to text and console based stuff (visiting BBS systems, reading text-only sites).
@@RetroSpector78 True, the oldest PC that I have now that I did managed to get some internet on is a Toshiba Satellite 330cds from 1998. I have it running Windows 98se and it has a 266 mhz Pentium cpu with 96 mb ram. I could do some albeit limited web browsing on it like check the weather on the old msn site and do simple google searches and thats about it.
zoomosis yep, that one even works on an XT. You can get a patched version of microsoft network client also running on an xt, but it is a bit more of a hassle to install. If you have a packet driver and only need basic tcp-ip stuff , mTCP is a great option.
@@RetroSpector78 nein :) having at least 1MB of RAM and VGA you can experience the magic of the WWW in its full 256 colors glory 😁 yes, even aniGIFs! All you need is Arachne/286 browser.
i have a Compaq portable, it had two shorted tantalums on the motherboard that i replaced, later on i pulled it out and powered it up and it blew out smoke out of the side vent lol, it turned out to be another tantalum that cooked itself inside the PSU, they are all ticking timebombs lol
64K of bad sectors is no big deal for an MFM drive that old. It's great that it's still working at all. I'd only be concerned if it began developing many more bad sectors. But obviously you're not going to be keeping any important data on it. :) I have a Compaq Portable II and a generic beige 386DX40, both with CF to IDE adapters and a huge 2 GB CF card installed. They work well, although you need to use Ontrack Disk Manager to use them because the BIOSes of each don't natively support such large capacity drives. Obviously it means the PCs aren't "stock" any more (the 386 also has a GoTek drive installed) but it makes them both much more convenient to use.
I have a mid 90's vintage machine that I maxed out to a P233MMX with 256mb ram, forgot the harddrive size, but being that its pushing 20 years old, I want to put an IDE to CF adapter in it, how easy is it to just transfer the entire HD to the CF and boot from that exclusively?
Personally, I would've left the 5.25" drive as Drive A, and the 3.5" one as Drive B. That's how I had my old 286 computer set up. What I don't remember is if our harddrive was also MFM or already IDE.
I left it “stock”. The 5.25 drive was from 1990 so probably installed as part of an upgrade when 3.5inch disks became more mainstream then 5.25inch. But who knows what we’ll do in part 3
Very unusual to see red LEDs on 1.44M and 1.2M floppy drives. Most of them are green. Never have seen a 720K or 360K drive with anything but a red LED.
There was also similar program called XTreeLink that came with XTreeGold 3.0, which I preferred over Interlnk. Also popular was LapLink, though I never used that.
zoomosis correct, they even named a cable after it :) I thought Norton Commander also had an option, but I think it’s only in a version greater than 4.0 as I haven’t found the option in my version.
mnd not many pieces of software on a cdrom were made for 286. Think a soundcard + nic is a better option. Also don’t like the look of a cdrom on a 286 but that’s just personal preference I guess.
Wow, I would have known into full paranoid mode. I'd check the ISA slot, the motherboard traces and who knows what before considering the possibility that it was just a coincidence that two cards blew the same cap one after another.
4:42 helpful rule of thumb: the red line on the ribbon cable plugs in on the side of the power cable.
But not all 3.5" floppy drives follow that convention.
That rule is only for hard disk cables.
@@juniorbcm5375 I've seen a few older hard drives with pin 1 opposite the power connector. Much less common than on floppy drives.
80’s tantalum capacitors always blow up. It’s not an if, it’s a when.
Just bumped on your channel, and wow! There are several good retro PC hardware channels out there, but yours is the only one who explains this stuff properly how these things work electrically. In the end, circuits are simple, but you actually show how troubleshooting and fixing these should be done. Thumbs up!
Charlie Foxtrot thx a lot man ! Really appreciate it .... lots more to come...
Some years ago I found a motherboard with a 286 thrown in an old building that was being demolished, and I was lucky that it is working perfectly. Now I think I can make it work when I buy some pieces and have it in my small collection, excellent video
Yeah 286 is also a really nice platform. They are speed devils compared to those xt machines :) and you can get away with using standard 16 bit cards that are easier to find.
@@RetroSpector78 I plan to buy a gotek emulator from floppys to be able to install some programs easier
Excellent plan. They are very convenient. I use them also but only to bootstrap the pc’s and install some drivers as I setup the machines. I don’t like the look of a gotek in such an old machine. I am also planning to network all of my retro pc’s. have dozens of nics and have setup a nas with all of my retro stuff... that way I can easily hook them up to the network and copy stuff over. Just a matter of inserting a nic and configuring it for msdos or windows.
@@RetroSpector78 Do you know any old software library internet site that you can recommend?
@@RetroSpector78 ISTR someone nodding a 3.5" floppy and drive to mount a SD card in the disk and contacts for the card reader in the drive.
Still looking for part 3......
Also, where a HDD has a defect list. there will be bad sectors and "attempting to recover allocation unit ...". The defect mapping in low level format marks the track as explicitly bad, so the high level format will have to mark it bad, rather than relying on the high level format detecting them and maybe missing them if they are not "bad enough"
Good video. I really enjoy watching these old machines bring back to life. I whish I still had one.
thanks ... check out some of my other videos ... lots more where that came from. And if you like you can subscribe / like / share ... to help support the channel ...
RetroSpector78 heb ik al lang gedaan☺️
Looking forward to Part 3. Have you addressed the CMOS battery or are you setting the hard drive etc every start up?
Yes.
Where did part 3 end up please?
2 tantalum capacitors disliked this video.
I remember buying a dual processor p200 at a computer store back a few years. Guy gave me a similar machine with it for parts. It was a disaster. It took ages to figure out what was going on and getting it to work. I learned a lot in the process, but from then I always named the box "Disaster". I do miss that machine. I have absolutely zero need for it but it was a lot of fun learning about threaded coding.
Unable to find part 3.. probably due to ram conflict or some error.. maybee my disc has gone bad - seek error or bad sectors??
All PC Floppies (with a few execptions of course like on the A2088) are configured as B: (DS1). The twist in the cable is what makes them A:, by swapping DS0 and DS1 signals and the Motor Enable Signal. Most floppies are hardwired to be DS1 bute some have the jumpers exposed.
Another nice video. Well done. Re 3.5" FDD. Where as with most IDE drives the red-striped pin one is generally always towards the power connector, 3.5" FDD's ..all bets are off. I've even one baffling one where it has a knotch in the PCB (but not a keyed connector) to allow for a ribbon cable knotch .. and it goes the other way around. Also some drives when you get them the other way around, if there's a bootable disk in there when it lights up, it'll scramble it. Again, well done and looking forward to more of your videos. Great they're a little technical.
Great work on restoring this thing so far. The only thing I have not seen repaired that i noticed in the first part was the leaking Varta battery for the CMOS. It didn't look like it had destroyed anything yet but there was definite signs of corrosion setting in. I would make sure to remove that and clean up the board before it eats away any traces. If you are looking for a good battery replacement, the 3.6v NiCad packs that cordless phones use work well for these old boards.
4:40 afaik PIN 0 (the marked one on the ribbon cable) always faces towards the power connector
Good work! It seems like capacitors are always a source of problems, in any electronic device - even in antique radios and tvs.
Correct ... old hard drives are also error prone. But other than that these old computers are pretty solid.
A 1/4 watt load resistor should make any of these old at’s start. You can put it on any rail I would do a 5v load. Back in the day 30 years ago you could buy a load pack or dummy load device. These were awesome bench power supplies
Great video. Love your diagnostic explanations and production values.
I absolutely love the previews at beginnings of your videos.
Yeah stopped doing that for some reason .... will pick it up again. Thx for reminding me :)
Ah, tantalum caps, the scourge of old PCs... ;)
Regarding the hard drive: I don't think a low-level format would help with the bad sectors. Remember the drive defects on the sticker? Back then, it was totally normal for hard drives to have factory defects. In my opinion it's better to have more sectors marked bad than to constantly get data errors because of data getting stored on defective areas. As long as the bad sectors don't get more, the drive is totally fine ;)
Anyhow, congratulations! That's a really nice PC.
I have read somewhere that performing a LLF could get rid of bad sectors, but we need to do a more detailed study on that. (Under what specific conditions).
@@RetroSpector78 That does work indeed, but only with modern drives which have defect management. Modern drives have spare blocks which the drive transparently uses to replace bad blocks. That's why modern drives appear to be defect-free until the spare blocks are all used up. "Low-level-formatting" these drives with the manufacturer's software reorders the blocks so the drive appears to be okay again.
@@kpanic23 modern drives or any IDE drive cannot be low level formatted...old stepper drives loose head and stepper alignment with time...much like floppy drives....LLF rewrites the track and sector structure so the misalignment is no longer a problem...it can make a huge difference in drive reliability, often getting rid of some bad sectors....also erasing wirting and reerasing constantly the same sectro (some software does that) can help revive the magnetic media....if the bad sector is a scratch or a speck of dust stuck to the drive then there is no possible remedy
Netjes gedaan! Heb je kanaal nog maar net een paar dagen geleden ontdekt. Mooie verzameling aan computers.
Bedankt ! Blij je hier te hebben ... geniet ervan zou ik zeggen ... genoeg content om deze corona tijden door te komen :)
@@RetroSpector78 Absoluut. Ik ga rustig alles eens bekijken!
Ben zelf ook een liefhebber van oude computers, maar dan wel van het socket 7 tijdperk. Ik vraag mij dan ook af of je niet eens onderdelen bij mij gekocht hebt. Ik heb destijds veel onderdelen, die ik niet meer gebruikte verkocht middels MP.
I'd swap all the caps on the cards where one failed, they were probably made in the same chain, have the same age and have lived with the same conditions, so it's only a matter of time before the other caps do this as well.
By the way, have you been to Lille (Risjel) last week-end ? there was the big annual flea market in the whole city, and there was some pretty cool stuff to catch there ^^
No I haven't ... never been to these kind of markets actually ... Should get out more :) Here we don't have thrift stores, and the only way to get good stuff is either online, or by word of mouth...
I would have swapped them all too.
All out of 10 microfarad caps .... but you're right .Best to replace them all while you're at it.
it seems like the capacitors are mostly for saving the circuits behind it to not damage more in case of problems in the circuit.. did i get it right?
I would recommend using Norton Calibrate to test any suspect MFM/RLL hard disks. Sometimes it can take a few days to test a large MFM drive, though.
I'd be worried that the -12v rail is putting out a positive voltage. Tantrums very often explode when reverse biased. Did you check the -12v rail? It's normally provided by a LM7912 negative linear regulator and those fail short (which could give you a positive voltage in some cases).
The RS232 cards use -12v to provide the mark voltage.
Hi, I have a RGB graphics card with the same problem, one of the tantulum capacitors has exploded. The bad capacitor is connected to rail +12v and i would like to know what are the specs i have to look for to buy a new one. I can only read 106F on it. Also, it would be great to have some info about this very large graphic card, i couldnt find any brand name on the PCB, only CGP-880 and it was made in taiwan. Thanks
Come for the exploding capacitor light show. Stay for the fully functional 286. :)
Is that a loose screw sticking to the underside of the floppy drive at 1:47? I see it again at 3:05... still watching, waiting to see if he notices it...
Angela Walker spoiler alert : he didn’t ? :) But I do vaguely recall a situation with a missing screw and a diskdrive. But not 100% sure if it was with this one :)
I would use GRC's Spinrite on those old HDD's back in the day. Amazing program by an amazing guy who did it all in assembly or something.
I know its been a long time, but did you see that there is a loose screw on the floppy drive spinner thingy ?
I remember having an old scsi hard drive with bad sectors, I used scandisk on it over and over until it had a clean slate... It shrunk from 105mb to about 90.... :( This was the first drive I ever had in my 386 when I was a kid in about 1993 or so.
With floppy drives, generally the red stripe on the cable (pin 1) points towards the power connector :-)
Still on the lookout for part 3 .... :x
A PC thats about as old as I am, I was born in 1984. Is it possible to use the Internet on something that old?
You won't be visiting any flashy new websites soon on this thing :) But you can get it connected to the internet using tcp/ip that's for sure. But your internet experience will be limited to text and console based stuff (visiting BBS systems, reading text-only sites).
@@RetroSpector78 True, the oldest PC that I have now that I did managed to get some internet on is a Toshiba Satellite 330cds from 1998. I have it running Windows 98se and it has a 266 mhz Pentium cpu with 96 mb ram. I could do some albeit limited web browsing on it like check the weather on the old msn site and do simple google searches and thats about it.
You can. Look at the mTCP software by Michael Brutman.
zoomosis yep, that one even works on an XT. You can get a patched version of microsoft network client also running on an xt, but it is a bit more of a hassle to install. If you have a packet driver and only need basic tcp-ip stuff , mTCP is a great option.
@@RetroSpector78 nein :) having at least 1MB of RAM and VGA you can experience the magic of the WWW in its full 256 colors glory 😁 yes, even aniGIFs!
All you need is Arachne/286 browser.
Very interesting. Whats about Part 3? 🙂
i have a Compaq portable, it had two shorted tantalums on the motherboard that i replaced, later on i pulled it out and powered it up and it blew out smoke out of the side vent lol, it turned out to be another tantalum that cooked itself inside the PSU, they are all ticking timebombs lol
Part 3? :)
64K of bad sectors is no big deal for an MFM drive that old. It's great that it's still working at all. I'd only be concerned if it began developing many more bad sectors. But obviously you're not going to be keeping any important data on it. :)
I have a Compaq Portable II and a generic beige 386DX40, both with CF to IDE adapters and a huge 2 GB CF card installed. They work well, although you need to use Ontrack Disk Manager to use them because the BIOSes of each don't natively support such large capacity drives. Obviously it means the PCs aren't "stock" any more (the 386 also has a GoTek drive installed) but it makes them both much more convenient to use.
I have a mid 90's vintage machine that I maxed out to a P233MMX with 256mb ram, forgot the harddrive size, but being that its pushing 20 years old, I want to put an IDE to CF adapter in it, how easy is it to just transfer the entire HD to the CF and boot from that exclusively?
Looking at the problems you had with this machine, I wouldn't say it was from hell, more like purgatory.
great work so far!
Thx ... almost there ... :)
where is part 3?
Personally, I would've left the 5.25" drive as Drive A, and the 3.5" one as Drive B. That's how I had my old 286 computer set up. What I don't remember is if our harddrive was also MFM or already IDE.
I left it “stock”. The 5.25 drive was from 1990 so probably installed as part of an upgrade when 3.5inch disks became more mainstream then 5.25inch. But who knows what we’ll do in part 3
Very unusual to see red LEDs on 1.44M and 1.2M floppy drives. Most of them are green. Never have seen a 720K or 360K drive with anything but a red LED.
I fancy your channel. I have just subscribed.
Thx a lot ! Much appreciated
Thanks for mentioning intersrv an interlnk :)
Thank god most systems have a serial and/or parallel port :)
There was also similar program called XTreeLink that came with XTreeGold 3.0, which I preferred over Interlnk. Also popular was LapLink, though I never used that.
zoomosis correct, they even named a cable after it :) I thought Norton Commander also had an option, but I think it’s only in a version greater than 4.0 as I haven’t found the option in my version.
@@RetroSpector78 Yes, I think that feature was only provided with NC 5.0 and later.
Yes, the hard drive should have been low-level formatted
Are you Flemish?
nice video
20 meg very little smallest I had 30 meg it still works great
nice!
Put a cd-rom drive also if you're going to install a sound card :)
mnd not many pieces of software on a cdrom were made for 286. Think a soundcard + nic is a better option. Also don’t like the look of a cdrom on a 286 but that’s just personal preference I guess.
The past of put is put not putted
👍😊😎😇sweet
Where's SSD ?
Where's CPU Cooling ?
WTF? This can't be computer.
I don’t know why I enjoy watching these super lame PCs. The time I watched a guy trying to fix a monitor a cap blew. I was then wearing my coffee.
All x86s come from heaven. Only x66s come from hell :P
there is no part 3 you liar hahahaha