Everything went perfect tile the final tests. PS board voltages all check. Shunt reg board all LED's light and voltages check. All resistances at terminals and valve pins check (some on the 15% high side). Plug in tubes and power on. Right channel LED's on C4S don't light one of the right side LED's on the shunt reg is now very dim (1 closest to PS board) and the other is dark. Voltage readings on left side are low at IA and 0A. Right side readings are no existent or way off. Read a bit on forum and decide to check filament readings. Spot on 6.3 at PS board, and tube pins. But (and it is a big but) while checking this the front 220uf Cap on the PS board expands and breaks plastic casing (polarity is correct). Did running it long enough with reg board not working properly cause the cap to explode or or was the cap bad? Also where to I look for the problem that is causing the right side LED's not to light? :'(