Chosen Solution
So, how do I troubleshoot this? The TV only works if I manually press the relay on the power supply board, after I do that it will stay energized. It appears to not be getting some kind of control voltage to energize it and keep it energized so the power required to operate the TV can get to the rest of the TV from the PS board. I noticed that there is no 5v (standby?) voltage constantly at the relay even when the TV is off (I think it’s supposed to be there ?) Sometimes after pressing this relay it will not stay energized, in this condition, I was able to measure 5 v across the relay which indicates that the other side of the relay is not allowing current to flow through it. I’ m thinking there is something in the standby circuitry that may be the culprit? Philips TV Model 42PFL7422D/37 SN: YA1B0729020266
Hi, Here are some images of the standby voltage circuit from the service manual that may help.
(click on image) Hopefully a start
