Check the voltages at the cpu input connector J210, You should have 12VDC between pins 1 and 7and 5VDC between pins 1 and 5. Check for any cracked solder on the circuit board at this connector. You could also remove the board and connect it to a test power supply with a 5VDC and 12VDC output to see if the board fires up. This may isolate the problem to the CPU or the power driver board. An old computer power supply will work.
