Hi. Sorry don't know much about motherboards. My motherboard has broken. It is a Lenovo Thinkcentre Rev: 0.21.
I spotted a later motherboard revision on ebay Rev: 1.0.
It has the same Intel 775 duo core socket and the same Ram slots.
Mine had a Intel G33/31 chipset and the one on Ebay is North Bridge - Intel Q35
South Bridge - ICH9DO
I wondered if this would work as a replacement.