On any reset for flippers, I always start with checking the 5v from the driver, through the driver connector (back end of the IDC), then the Z (if applicable), then the back and of the cpu 5v connector, then the 5v on the CPU - BEFORE disconnecting a thing. Drops in connectors are the main problem, and this gives you a point where there is an issue usually.
Reseating which seems to correct the issue is only temporary. After this I check the wall voltage, I look to br2 and it's cap, sometimes the power cord (thin computer ones can cause this), and sometimes I have found the problem lies in the lower cab connections from the transformer.
Sanford, NC
