Help on erratic bahaviour on AOC TV

[CHexclaim]

Dear all,

First of all I always appreciate the feedback people give me when I ask for help on the forum and thank you all for that.

The issue I am having now is with an AOC L42H961 TV. It works fine but after some time it trips the earth leakage protector in the power panel on the house. I think it can be a leaky capacitor in the power supply but if anybody has any similar experience or a service manual it will be of great help.

Thanks, CH!

[kfitch42]

Well, if it is really the earth leakage protection that is tripping, then (I think) you would need something shorting to earth (the grounded case?) for that to happen. A capacitor that is failing shorted would normally cause an overcurrent trip. In either case the first thing to do is open her up (and discharge capacitors) and have a look around. Is anything: loose? discolored? bulging? or just look plain fishy?

Until you post something more substantial (like pics) I don't think we can help very much.

[Seekonk]

Does it have an earth ground (many TV are just two wire power) or antenna/cable attached.  It needs some ground path to trip the circuit.  If not internal arcing of a component can sometimes trip it.

[CHexclaim]

I am expecting to open the unit tomorrow. I haven't been able to do so yet.

I did unplug everything from the TV and it still trips the protection. The TV has an earth pin that if isolated, the protection does not trip (obviously).

I was thinking about filter capacitors to earth in the front end of the PS being leaky. I will look these or something loose or broken. I will update with my findings.

Thanks. CH!

[wraper]

There are not many parts to leak: 1. most likely two of Y class capacitors (blue color), 2. transformer, 3. optocoupler(s) - though very unlikely, 4. inlet connector (though it will leak only of contaminated or have burned (carbonized for some reason).
Except those, that could be only PCB contamination with some crap. For example, electrolyte which leaked from some cap. Or some foreign conductive object on the PCB.
BTW, try different power cable or measure it as it could be faulty too. Anyway, it would be a good idea to measure a resistance from live wires to the earth. Also do not forget that PSU PCB carry high voltage electrolytic capacitor(s) which most likely will hold the charge even after the TV is disconnected from the mains voltage.