Papcina wrote:
yes ano about the capacitors... but what when a mobo gives no sign of
being alive? the capacitors r fine, bios is reflashed and no visible
sign of burnt stuff? how to find an error in that case?
FETs works normally, every other bigger chip is wroking fine...

any ideas where to check more?

Check the RAM. Those old DIMM slots suffer frequently from bent pins.
Also try another RAM stick (DIMMS must be in pairs).
Then try to replace the CPU, supply and video card.