Dude that is true, but Iv yet to experience their failure. Not meaning that it will not happen, but when it does they pop and you just need to swap em out.

ODwilly wrote:

Bad tantalum caps are fine, as far as I know. At least until they literally EXPLODE. (no joke)

Is there a way to detect upcoming failures? I surely hope so.

All capacitors go out of spec and blow at some stage... it is both unavoidable and inevitable.

Get a soldering iron and learn to solder! 😎

computergeek92 wrote:

ODwilly wrote:

Bad tantalum caps are fine, as far as I know. At least until they literally EXPLODE. (no joke)

Is there a way to detect upcoming failures? I surely hope so.

The only way you can measure a cap is to de-solder it from the board it is on and measure it with a meter to find specific capacitance and compare it against it's rating, or conductance with a DMM if you want to perform a basic open / closed circuit test i.e. to see if it's dead!

Once you de-solder it though... there is little point putting the same part back in, so you may as well fit a new one.

I think tantalum's can be better than most caps in the sense that they dont ruin parts mostly. EDIT:IDK I am to drunk to realistically be unbiased

ODwilly wrote:

I think tantalum's can be better than most caps in the sense that they dont ruin parts mostly. EDIT:IDK I am to drunk to realistically be unbiased

You're right... all the tants that have blown on me just destroy themselves like a kamikaze lemming. The rest of the board always remains intact... although there is an open connection where the lemming used to be... erm, I mean tant cap.

I was with you... 9 hours ago, on the water now! 😵

LoL well I guess that’s better than electrolyte caps leaking over..

Hey I noticed that on every slot 1 cpu there is a single yellow tantalum cap. (on the cpu board) Would the thing eventually blow up?? Has this ever happened to anyone?

I heard UXWBill call tantalum caps this once, I think, and it's stuck for me ever since -- he called them "tantrum" capacitors in some kind of tongue-tied situation, as I remember. I've had 2 tantalums go 'bang', as well as plenty of P4 boards ruined by vented electrolytics. To be clear, I do know how to solder -- I just don't really have the coordination to do it well without spending hours on it, my hands are just too jittery.

ODwilly wrote:

Dude that is true, but Iv yet to experience their failure. Not meaning that it will not happen, but when it does they pop and you just need to swap em out.

It's like a fire cracker, scared the shit outa me! 😲

I bought a new in box Everex EGA card earlier this year and it had a bad tantalum cap on it that was shorted out and would prevent my IBM 5150 from powering on when the card was installed. Not surprising, considering the card was 25+ years old. The cap didn't pop or shoot sparks, it simply didn't work.

Just to get it done fast I replaced it with an electrolytic of the same value that I had lying around and it has worked flawlessly ever since.

As for other types of caps... Plan on replacing ones from the early to mid 2000s at some point, try to keep the system cool, clean and cleanly powered. The worst caps I've seen have been in systems that were clogged with dust and being powered by garbage PSUs that were also clogged with dust.

Other caps that I've seen go bad frequently are mid-90s SMD aluminum caps like the ones find on early Voodoo Graphics cards... IBM Model M2 keyboards seem to have a similar problem with these. I have a pristine looking M2 that is nonfunctional due to several traces on the flexible plastic key-PCB (can't remember the word for it) being blackened, likely caused by the leaking SMD cap I had to replace. I'd love to get it working because it is spotless externally... but that cap ruined the internals.

Ozzuneoj wrote:

I bought a new in box Everex EGA card earlier this year and it had a bad tantalum cap on it that was shorted out and would preve […]
Show full quote

I bought a new in box Everex EGA card earlier this year and it had a bad tantalum cap on it that was shorted out and would prevent my IBM 5150 from powering on when the card was installed. Not surprising, considering the card was 25+ years old. The cap didn't pop or shoot sparks, it simply didn't work.

Just to get it done fast I replaced it with an electrolytic of the same value that I had lying around and it has worked flawlessly ever since.

As for other types of caps... Plan on replacing ones from the early to mid 2000s at some point, try to keep the system cool, clean and cleanly powered. The worst caps I've seen have been in systems that were clogged with dust and being powered by garbage PSUs that were also clogged with dust.

Other caps that I've seen go bad frequently are mid-90s SMD aluminum caps like the ones find on early Voodoo Graphics cards... IBM Model M2 keyboards seem to have a similar problem with these. I have a pristine looking M2 that is nonfunctional due to several traces on the flexible plastic key-PCB (can't remember the word for it) being blackened, likely caused by the leaking SMD cap I had to replace. I'd love to get it working because it is spotless externally... but that cap ruined the internals.

So you found out the card did not work due a silently failed tantalem cap? I would've thrown out the card thinking it died from esd or electromigration. You are a genius.

computergeek92 wrote:

Ozzuneoj wrote:

I bought a new in box Everex EGA card earlier this year and it had a bad tantalum cap on it that was shorted out and would preve […]
Show full quote

I bought a new in box Everex EGA card earlier this year and it had a bad tantalum cap on it that was shorted out and would prevent my IBM 5150 from powering on when the card was installed. Not surprising, considering the card was 25+ years old. The cap didn't pop or shoot sparks, it simply didn't work.

Just to get it done fast I replaced it with an electrolytic of the same value that I had lying around and it has worked flawlessly ever since.

As for other types of caps... Plan on replacing ones from the early to mid 2000s at some point, try to keep the system cool, clean and cleanly powered. The worst caps I've seen have been in systems that were clogged with dust and being powered by garbage PSUs that were also clogged with dust.

Other caps that I've seen go bad frequently are mid-90s SMD aluminum caps like the ones find on early Voodoo Graphics cards... IBM Model M2 keyboards seem to have a similar problem with these. I have a pristine looking M2 that is nonfunctional due to several traces on the flexible plastic key-PCB (can't remember the word for it) being blackened, likely caused by the leaking SMD cap I had to replace. I'd love to get it working because it is spotless externally... but that cap ruined the internals.

So you found out the card did not work due a silently failed tantalem cap? I would've thrown out the card thinking it died from esd or electromigration. You are a genius.

I don't know squat about circuits. I knew that tantalums that haven't been used in decades are the most common cause of problems in old cards like these, so I did some googling. By chance I stumbled across an old thread where someone had a very similar card that had failed and shot sparks out of a tantalum cap. I documented it all here because I was amazed that I was actually able to fix something for once. 🤣

Re: What retro activity did you get up to today?

Sedrosken wrote:

I heard UXWBill call tantalum caps this once, I think, and it's stuck for me ever since -- he called them "tantrum" capacitors in some kind of tongue-tied situation, as I remember. I've had 2 tantalums go 'bang', as well as plenty of P4 boards ruined by vented electrolytics. To be clear, I do know how to solder -- I just don't really have the coordination to do it well without spending hours on it, my hands are just too jittery.

I think that was intentional 😉 He's famous for his smoke tests after all!

Jo22 wrote:

Wheren't there also bad caps around in the early 90s ?
I heard that the handheld consoles from Sega had them installed.

Bad capacitors are frequently found in the Sega Game Gear, and almost all of the NEC Turbgrafx / PCengine products. Frequently all you need to do to fix them is solder in new ones. Some people even sell capacitor kits for them.

On some boards I often find that only the VRM out caps with 6.3V are shot. They are usually 3300 uF or similar. AFAIK they "in front" of Vcore and get a pretty decent workout and some high temperatures. Tower coolers apparently aren't that great for these caps, the older style sunflower coolers seem to look after them better.

PhilsComputerLab wrote:

On some boards I often find that only the VRM out caps with 6.3V are shot. They are usually 3300 uF or similar. AFAIK they "in front" of Vcore and get a pretty decent workout and some high temperatures. Tower coolers apparently aren't that great for these caps, the older style sunflower coolers seem to look after them better.

Yeah the high temp from heatsinks isn't good for electrolytics. I have a dual socket 370 where a few caps was placed right next to one of the sockets and they cooked. I ended up relocating one of the capacitors away from its original position so I could mount new heatsinks to the board. Fun little project :p

On higher powered boards, I like to replace those with polymer caps. Lower ESR and high ripple current work well here.

Just received and repaired a KT7A (using a kit from badcaps.net). Strangely all the JACKCON were completely fine, however there were a bunch of "JPCON" that went bad. I changed them all just in case.

The board is not fully working, even after the repair. In particular the keyboard PS/2 port and the parallel port seem dead. However since the BIOS has great support for USB keyboard this is not a huge issue. OTOH the mouse PS/2 and ISA ports are fine.

Aw, the Great Capacitor Plague. Affected a lot of Mac's as well.

I have an iMac G5 that literally had all the caps blown. That was fun to replace.