VOGONS


First post, by Aragorn

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Having some issues trying to get this Athlon build up and running.

Specs are Athlon 1100, MSI K7T Pro2, 256MB Ram. Originally had a Quadro 2 Pro AGP graphics card, but also tried a TNT and a Matrox with the same result. Parts predominantly sourced from ebay.

The problem:

I powered the machine up this morning, all working fine. Ran thru windows 98 setup, formatted drives etc, got past the first reboot and eventually reached the stage where its asking for inputs (computer name, CD key etc). As i'm entering the key, i hear a tiny click from the PC speaker and the monitor blacks out.

Rebooted it and nothing, no video, no beep codes, just a black screen.

Tried a few graphics cards and eventually realised that if i leave it off for a while, it will bring up the bios screens, sometimes even make it thru post and "beep", then the screen goes black. If i try again, it will just remain black, or you might get a bit less of the POST. Usually you can hear the same click from the PC speaker that it made when it first died.

I've tried a different known good PSU, pulled all the PCI cards leaving just the graphics card, tried reseating the ram into a different slot.

Its sort of looking like a bad motherboard or CPU?

Reply 4 of 11, by Aragorn

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Digging around in older threads from when these boards were relatively current finds similar symptoms, and lots of mentions of the "Chhsi" caps that this board is littered with being trash.

So i've gone for it and ordered 18 caps from CPC.

Reply 5 of 11, by bakemono

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Capacitors might be correct, but to me it also sounds like possible thermal overload. Perhaps this board has one of those temp sensor "prongs" under the CPU and maybe the heatsink isn't quite flat against the CPU, allowing it to get hot...

Reply 6 of 11, by Aragorn

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I pulled the cooler yesterday to get the board out for the caps, the thermal paste looked nicely spread and had a nice even pattern.
The time between failure didn't seem right for thermal type issues, after it failed, even after leaving it several hours the most I'd get out of it was a few seconds of post. Whereas initially it ran for well over an hour.
Caps are here. Fingers crossed they swap easily 😀

Reply 7 of 11, by Aragorn

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Well i pulled two of the caps off, one that was showing signs of leaking and the other that was the same type. Both rated 2700uf 6.3v.

One measured 500uf and the other measured 900uf with my basic meter. So the caps are clearly faulty with significantly less than design capacity.

Unfortunately my solder wick doesnt seem effective so i'm going to have to wait till tomorrow when i can take the board into work, and use the sucker to clean out the holes, then i can install my new Panasonic caps.

I'll pull the rest of the caps out tomorrow at work, no point me trying to do it here without the right equipment.

I've also realised that the 10 smaller 1000uf caps i bought are a different shape to the originals, shorter and fatter, which might make installing them a bit awkward in some locations. I guess i'll see how i get on, and if they wont fit i'll reorder.

Reply 8 of 11, by Aragorn

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Ok so... Got it all recapped, stuck it back together tonight and started it up...

Its exactly the same. First try i got to the windows 98 splash screen, and it died. second attempt it got a tiny bit further and died again.

Any Ideas?

Reply 9 of 11, by Aragorn

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After some scouring i noticed a lot of heat coming from the FETs above the CPU. Some searching on the part numbers uncovered this thread on a polish forum:

https://www.elektroda.pl/rtvforum/topic143618.html

As well as various other sites pointing to issues with the SC1155 driver chip for the voltage regulator. Geh!

Reply 11 of 11, by Socket3

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I encountered this issue on several boards, latest of witch was an Asus A7V133. A complete recap fixed it completely. On my MSI K7T a simple recap did not work - the board was unstable. It would boot into windows but hang or re-boot whenever I launched a 3D app or game. Finally I replaced four mosfets at the top of the CPU socket with slightly out of spec parts from a newer board and now it works a treat.