So swapped mpus from a tales from the crypt that was working just fine to a royal rumble I just picked up to try to diagnose some some issue with it. Swapped the mpu back into tales from the crypt and now my controlled lighting isn't working. It will either blow the F4 fuse or the 8a by the big blue cap. If I check the voltage at f4 on the power supply is reading 19.8. checking the positive at the big blue cap is 19.8 on the purple wire. Blue and white wires are 7.8-8.0. Bridge rectifier checked out fine. Looking for suggestions on what to do next?