I have an LG TV model 32LD650N. It's about 9 years old. The last year it has been slower and slower to turn on. When I power it on, the red LED flashes (normal during power on) but the screen stays off. After ~15 minutes turning if off and on again would make the screen go on. The TV would work fine from there.
But now it just stays on the blinking power LED trying to turn on.
What I have tried:
I am very much a beginner when it comes to electronics repair. But I suspected a bad capacitor on the power-supply.
After disassembly there was nothing to see during the visual inspection. All the caps look fine.
The power-supply has 3 voltages (3.5v, 12v, 20v) and is connected to the 'signal board' with a 24 pin cable.
The power-board has 2 fuses, both of which I measured and they are OK.
The supply has 2 other connections going directly to the screen (marked with 1 on the annotated images).
Measurements:
When the supply is not connected to the signal board I can only measure 3.5v on the 24 pin jack.
When the signal board is connected and the TV is trying to turn on, all 3 voltages are present on the 24 pin jack.
Checking the caps:
Next I de-soldered all of the electrolytic capacitors, one at a time. (Except 2 big ones on the primary side, they are glued down with some white adhesive).
They all measured fine on my multimeter. 10% within the printed value. I can see nothing wrong with them.
Since I was unable to de-solder the two big caps I have not been able to measure them. But they look fine...
What's next?
I have no idea what to try next so I'm posting here for some guidance.
It's seems impossible to remove the big glued caps without damaging them. Any tips on removing the adhesive?
Any ideas or advice on what to do next is very welcome.
But now it just stays on the blinking power LED trying to turn on.
What I have tried:
I am very much a beginner when it comes to electronics repair. But I suspected a bad capacitor on the power-supply.
After disassembly there was nothing to see during the visual inspection. All the caps look fine.
The power-supply has 3 voltages (3.5v, 12v, 20v) and is connected to the 'signal board' with a 24 pin cable.
The power-board has 2 fuses, both of which I measured and they are OK.
The supply has 2 other connections going directly to the screen (marked with 1 on the annotated images).
Measurements:
When the supply is not connected to the signal board I can only measure 3.5v on the 24 pin jack.
When the signal board is connected and the TV is trying to turn on, all 3 voltages are present on the 24 pin jack.
Checking the caps:
Next I de-soldered all of the electrolytic capacitors, one at a time. (Except 2 big ones on the primary side, they are glued down with some white adhesive).
They all measured fine on my multimeter. 10% within the printed value. I can see nothing wrong with them.
Since I was unable to de-solder the two big caps I have not been able to measure them. But they look fine...
What's next?
I have no idea what to try next so I'm posting here for some guidance.
It's seems impossible to remove the big glued caps without damaging them. Any tips on removing the adhesive?
Any ideas or advice on what to do next is very welcome.
Comment