Hello all!
To start: my knowledge about electronics is not very good but I'm eager to learn!
Today I got a
Sony KDL-42EX410 from a friend and it has the following issue:
When you plug the device in the power/standby LED lights green and stays green. When you turn on the TV the backlight lits and the Sony logo shows. At that moment the screen turns of, the power/standy LED fades to almost out. Then the screen turns on again, green led to full on and it reboots again. This keeps repeating.
The reason why I suspect a power problem is the fading power/standby LED (correct me if I'm wrong). I used the EEVBlog BM235 to measure some capacitors but I know it's hard/impossible to measure caps in circuit.
I disconnected the backlight
LED inverter and the problem persists. So I think I can make sure this board is not part of the problem.
I took a high-res picture of the Sony APS-308 power supply with the capacitor values next to it:
The two caps on the left top (just under the type number) are 470µF each and when I measure I get 1226µF (or sometimes even higher) and I suspect these are in parallel with some others.
I also created a picture of the back:
What would be the right next step to diagnose this issue?
Edit:
I replaced the power supply and the problem persists. With only the main board connected I see the same problem so the problem should be in there is my guess.
Video of the problem:
- DJVG