The board had one burned Mosfet in CPU supply witch make shortcut +12v to null and it didn`t want to turn on even on force.When I changed that transistor board turned on normaly but North bridge was wery hot after few secunds. I changed Q117, Q198 (15N03H between AGP and RAM slots) in North Bridge supply (I found on your forum that northbridge supply is taken from that two transistors but can`t be sure) that were also wery hot but nothing changed. .All other voltages (CPU, RAM, AGP,South...) are OK.South Bridge is normaly warm.
Is North bridge fried?