Hi. I have the same problem with my Hitachi P50S601. I have changed out the swollen caps but that didn't do the trick. Further troubleshooting, I have disconnected each and then both SDU boards, same flashing light issue. I disconnected the Y-SUS board, same issue. Then, disconnected X-SUS board, same issue. When I disconnected the logic board, the TV stayed on (but no picture). So, does this mean I just need to replace the logic board?