Bad caps (?) on FIC VT-501

[AK0R]

I have a FIC VT-501 (200 MHz Pentium I) that, until recently, was my main computer. I've since upgraded to a P4, because the VT-501 machine stopped working.

The system was periodically unstable, nothing consistent. There is no visible evidence of bad capacitor plague on the motherboard or any peripheral card; however, nothing comes up on the screen when the computer is booted, although the computer acts normal. I'd like to keep it going, as it runs (ran) my 7-year-old's games quite well.

On the motherboard, there are nine 1000μF, 10V, 105°C capacitors labeled S.I. and something that looks like a not quite filled-in circle. My web research has failed to turn up the manufacturer. There are also fifteen 10μF, 25V, 105°C and one 100μF, 10V, 105°C units, all made by Su'scon, an identified bad performer.

There are no electrolytic capacitors on the video card (Diamond Stealth II S220).

There are two 470μF, 16V, 105°C capacitors on the Aureal AU8220 sound card; again, the manufacturer is unknown. They have a flattened diamond with a filled-in circle at each of the points. On the side, they have:
LL
105°C
(M)
There are also seven 10μF, 25V, 105°C and one 47μF, 16V, 105° capacitors by GSC, another notoriously bad provider.

Fortunately, I have just enough 1000μF, 10V capacitors left over after BE6-II recapping to hit those on the motherboard first.

Can anyone help on the identity of the two manufacturers, as well as provide suggestions on troubleshooting/similar experiences?

[willawake]

did you check the monitor on another comp?
did you check the psu voltages?
is your speaker connected so you can hear post beeps?
instabilty could have been failing ram / dodgy psu / bad hdd / bad os?
do you have any other cards in there, take them all out except the vga and disconnect all drives then try to boot

forget about the little caps. forget about the caps on the sound card. if the sound card is worrying you then take it out, boot and see if the same problem is there. if you are gonna replace the caps then just do the 1000μF

personally i would have thrown the kitchen sink at it, trying another psu, another ram, another video card to eliminate possibilities until it is sure it is the board, although i do have a box full of items of that age to test with. if you dont have those options then i guess recapping is a good idea but i was under the opinion that PIs were too old to have the badcaps problem.

[AK0R]

I realized after I posted that I left out some useful information.

I know that the monitor works just fine, because I'm using it on the new computer. Every now and then, it gets a little flaky, but after all, it *IS* ten years old.

I haven't tried measuring any of the voltages with the system powered up yet. The internal case speaker is properly connected, and the board seems to post correctly (same number and spacing of beeps that I remember hearing before). I hadn't tried running any memory tests before, and now that I don't see anything on the screen, I can't, although memory is certainly a possibility (some of it's *shudder* 72-pin). The power supply is an AT (of course), so I don't have an available replacement. The HDD is a relatively new (about a year old) 40GB Maxtor. I believe the HDD is ok, because I was able to read from it and write to it when connected to the new computer. Also, the operating system on the old machine was Windows 98SE with updates, although none had been installed recently.

I wasn't thinking about bad capacitors in the sense of the plague, but just failure due to old age. The specs on most capacitors specify a lifetime of 1000-2000 hours, with 5000-6000 hours being the exception. It's been on that much in one year. This is actually the second case that machine has been in; the fan on the power supply gave out on its predecessor (the power supply was still working, although it was damn hot!). But it's been at least 5 years since I put it in the new case, so it's had some run time. Also, none of the capacitors on anything appear to be low ESR, so even replacing the big ones on the motherboard would probably be an improvement.

[willawake]

cap lifetimes are estimated at 105oC. Since the operating temperature is actually much less than that the expected lifetime is many times more, i forget the formula.....

if the caps say 105oC then they are possibly low esr. i agree that replacing them with a good brand would be a good move. old age is probably a factor on that old system

[HyperYagami]

It's a Pentium-1...

I'd rather ebay a P-2 board + CPU instead...probably cost just about the same as a bunch of new caps. Sometimes you just have to let go...

[AK0R]

Repairing a Pentium-1 System (Engineers)

It's a Pentium-1...

I'd rather ebay a P-2 board + CPU instead...probably cost just about the same as a bunch of new caps. Sometimes you just have to let go...

You, sir, are obviously not an engineer. You're an engineer if you've ever spent a weekend fixing a $5 transistor radio (or an obsolete computer). You're an engineer if you think everyone around you is yawning because they're tired. You're an engineer if your shirt, trousers, and socks aren't color-coordinated, and you don't care.

What you say: Engineering translation:
------------- ---------------------
It doesn't work. Oh no, someone waved a red flag!

It works. No, it doesn't.

It sorta works. No, it doesn't.

It works pretty good. Except for this, and this, and this, and ...

It works real good. Except for this and that.

It works perfectly. Now, we're getting somewhere.

The person who designed Now, it works.
this was a complete idiot.
After complete redesign,
it now works as it should
have in the first place.