Gigabyte 7VM400M-RZ

[pfrcom]

Pretty miffed when my 7VM400M-RZ stopped working, quite a handy board for testing Socket 462 processors

First try at resuscitation was replacing its larger capacitors, when that didn't work, all smaller ones as well



Still dead as, so I embarked upon what would usually be my first try, reprogramming the BIOS externally

Unfortunately Gigabyte being one of those $hit manufacturers who added a couple of cents to their profit margin by soldering BIOS chips directly to the board, I had to cut the chip out



solder in a socket



-then- program a replacement chip

Still no sign of life

I'm now considering a north bridge reflow, although have had one success

https://www.badcaps.net/forum/showthread.php?t=47708

and one failure with that

https://www.badcaps.net/forum/showthread.php?t=50171

Any suggestions?

[SMDFlea]

Re: Gigabyte 7VM400M-RZ

The schematic might help. Are you getting any voltage on the bios and power switch.

[piernov]

Re: Gigabyte 7VM400M-RZ

"no sign of life" is quite vague. No point in suspecting BIOS or MCH if there is no power at all and it doesn't even try to turn on when triggering power button.

[pfrcom]

Re: Gigabyte 7VM400M-RZ

"no sign of life" is quite vague. No point in suspecting BIOS or MCH if there is no power at all and it doesn't even try to turn on when triggering power button.

Poor choice of words - board always powers on, so no sign of POST would be more accurate

BTW here's pics meant to be in original, which I cannot now edit

[ChaosLegionnaire]

Re: Gigabyte 7VM400M-RZ

via board huh? since u had one success reflowing a via board, i say go for it again!

[momaka]

Re: Gigabyte 7VM400M-RZ

Hmmm. I see green Sanyo caps on those pics. Are they WG or WF series? If WF, you might want to replace them. They are known dud series, though they usually bulge the same way as United Chemicon KZG - i.e. typically when they are not used for a long time.

Other things to suggest:
- Did you try the board with a different stick of known good RAM? What happens if no RAM is installed? Motherboard beeping errors or not?
- Did you try re-installing the CPU. Old CPUs and sockets are usually very resilient against corrosion, but it doesn't hurt to try and reinstall the CPU a few times to clear any possible surface dirt on the contacts in the CPU socket.
- Was the CPU and RAM inserted and removed many times before? CPU and RAM sockets aren't meant for frequent component swapping, so if you did this every time you used the board, that could be a problem too. (Though it should be noted that CPU and RAM sockets can still probably take around 100 insertion cycles safely, so I doubt this is the issue here. Still had to mentioned it anyways, not knowing the history of the motherboard or how it was used.)
- Have a PCI POST card or can borrow one? Older boards are usually pretty decent about displaying POST codes on POST cards. The code is actually not that important, but rather seeing if the board is even trying to POST. This is handy for narrowing down the issue to voltage and/or enable signal problem or a component getting stuck at POST.

[pfrcom]

Re: Gigabyte 7VM400M-RZ

Green caps are recent Suncon, albeit from eBay, checked on Transistor Tester before use - replaced KZGs which looked fine before removal

Tried with several different RAM, varying from DDR266 to DDR400, seeing test CPU is a Duron 800

No beeps if no RAM

Duron recently removed to test on another board (ironically a PC Chips M810) to verify it was working

CPU hasn't been changed too often - something I try to avoid, especially with sockets having flimsy HSF clips

POST card's LED card showed No Signal as I recall - reason I wanted to try another BIOS chip

It's winter here in Southern Hemisphere - I'll probably try ChaosLegionnaire's suggestion when my garage becomes habitable again