Checksum error

Recommended by Wim's BIOS...

Motherboard is NOT dead.
Computer is a company computer for accounting - and has NOT had anything added or changed.

When started cold...get checksum error block v1.0
with "detecting floppy drive A media" and "Insert sys disk".
At this point - I turn off (shutdown by power button) and restart by power button and will restart fine. (Some times I have to do this 2 or 3 times). Most of the time - after its been running awhile it will warm boots without a problem.

Replaced the ram module - no change in behavior.

What should I suspect (replace) next, the power supply?
Thank you.
Sam

[Rainbow]

What board and CPU is that?
I'd test it with another power supply. Also check capacitors on the board, it they're not going to explode.

Soyo - SY6VBA133
Intel 650 Mhz CPU

I need to replace it before I can experiment with it
For right now - the computer just doesn't get turned off.

Sam