hello, what happens is that I have a 42-inch lg television that a week ago began to restart suddenly, sometimes turned off and did not turn on until disconnected from the outlet, sometimes the sound was going, and now to turn it on in a within 5 minutes or the buttons and the remote control are reset or stop responding, and I don't know what to do, I have already changed almost all the electrolytic capacitors of the source and it remains the same. A and 2 points that mark + B at the source, and one with the letter D, in a + B that goes to a small transformer mark of 17.9 to 18.3v, in the other + B that goes to the large transformer to be in stand by mark from 17.9 to 18.6v, but turning it on gives me a voltage that my multimeter cannot measure, when measuring it on the 200v scale it does not mark me anything, and when measuring it on the 700v scale it marks me a voltage of more than 1000v, and then in the part of the letter D that goes to the small transformer next to the first B +, it marks between 141 to 149v

possible capacitors at source ... try them all and I fail in lighting how have you measured in ac or cc?

update, comparing the standby voltages of when the TV is just connected and at the time of failure and seemingly shut down, the voltage of this point begins to drop from 15v to 9v and after a while it rises again, attached photo of the point from where it varies in the source diagram. I have not checked lamps because it is difficult for me to remove them from the TV and also the fault occurs even without connected lamps, link to the source diagram http://www.serwis-elektroniki.com.pl/wp-content/uploads/2017/ 10 / 710_17_1.pdf