My CPU (WPC-S) won't boot. All cables to the CPU board are removed except J210, which is the power from the driver board.
D19 is on.
D20 is off.
D21 is on.
D1 4.98V positive side, 4.77V negative side.
U21 pin 14 4.77V
U8 (RAM) pin 28 4.77V
U25 (Game ROM) pin 32 4.98V
Anyone knows where to start troubleshooting?