On Sun, 20 May 2007 16:51:37 -0400, "DaveM"
wrote:

If a motherboard is showing no signs of life, how can you say that every other
bigger chip is working fine? If the board is dead, meaning that it won't boot
up, or even run POST tests, then how are you checking the "bigger chips?
You can't assume anything in this case... everything has to be verified
conclusively. The only way that I can think of doing that in the case of a dead
motherboard is to unsolder the chips and put them on a known good board. Given
the lack of service information on any of the PC boards that have been produced
in the past 25 years, it's shooting in the dark.

There's no way to know. Fortunately, the big chips are very reliable.
They don't normally fail unless something really bad happened (like
excessive voltage from a bad power supply, or someone shorting
something out). Testing the chips is completely impractical. The
soldering equipment alone would cost thousands.

The way to trouble shoot a motherboard is to eliminate the few things
you can fix before scrapping the board. Once you eliminate the simple
stuff, it doesn't really matter whether it's a bad chipset chip, bad
internal connection on the board, or some other unfixable problem.

I've repaired a lot of boards by replacing exploded caps. I've also
replaced melted ATX power connectors. On one board, I even replaced
some bad voltage regulator transistors (they were over heated because
of bad caps). If you know the board suffered from a failed BIOS
flash, you can reprogram the flash chip (it helps if it's in a
socket).
Andy Cuffe