TV stopped powering on
My TV stopped powering on. It is a LG LED, Model: 55LV5400-UB. In the middle of a heat wave, I tried to make volume louder, there was a click and it turned off. Reset by unplugging failed, as did trying to force a reset by holding a power button. Normally, after pushing the power button: a red light would come on, fade out, be replaced by white, fade out and start to work. When turning off: a white light would come on, fade out and then TV would turn off. Now, after pushing the power button: a red light comes on, fades, is replaced by white, which fades, then white comes on again and fades without any image appearing. IE according to indicators: TV starts to power on and then immediately shuts down. The TV is about 10 years old but all capacitors on the power board look fine. The next step in diagnostics is to check output voltages on the power board but I have the following questions:
1. LG tech advice given for a similar TV (https://www.justanswer.com/tv-repair/7h2...) says to test outputs 'with NOTHING connected to the Power supply but AC power, the Main-board, and the little board that houses the Power Switch.' Mine doesn't have a connection from the power-board to the power switch board but does that mean I have to disconnect power supply board's ribbons on LED connectors and maybe something going from the main-board? [Also, this problem was resolved by replacing a main-board (not power-board)]
2. I can't seem to disconnect connectors with ribbon cables. LG uses some kind of a snap lock which I can't figure out and I don't want to break a connector. If there is a method to disconnecting them please share it.
3. The power board connector going to the main-board has 24 pins but not all pins are labeled with voltage numbers so how do I confirm what are the proper voltages on them? (Further, to access all 24 pins I need to disconnect yet another ribbon connector which I can't figure out...).
4. Finally, given that comments given here for a similar make and model:
My LG TV 55lv5500 suddenly turn black with no sound or picture.
confirm that the problem was resolved for several people with same or similar TV's not by replacing the power board but by re-flowing the chip on the main-board, should I even bother testing the output voltages or go straight into re-flowing?
Is this a good question?