LG55UH615T pulsating Redstanby LED

[wushumike]

Re: LG55UH615T pulsating Redstanby LED

Throw the wires on the cable, and you will find out where the problem is in the power supply or in the LED bar.

Already did that...confirm is not LED strip because the light switch side....

[wushumike]

Re: LG55UH615T pulsating Redstanby LED

Throw the wires on the cable, and you will find out where the problem is in the power supply or in the LED bar.

I did that already...Confirm not LED strip.

[lotas]

Re: LG55UH615T pulsating Redstanby LED

So the problem is in the power supply (led driver), the LED strips are in order.

[wushumike]

Re: LG55UH615T pulsating Redstanby LED

Throw the wires on the cable, and you will find out where the problem is in the power supply or in the LED bar.

I'll try Dav.P method to check the MOSFET and IC (I did purchase this IC 801 from Ebay but yet to arrive)

Nothing can get worse, any suggestion to nail the problem are welcome....Only last resort yo get another PS board.

[lotas]

Re: LG55UH615T pulsating Redstanby LED

Well, it's better not to use the TV now until you fix the problem in the led driver.
Do you know the IC801 number?

[wushumike]

Re: LG55UH615T pulsating Redstanby LED

IC 801 = MAP3516

I try searching for Datasheet... not available.
I can only assume this is a 2CH LED Backlight controller chip.

[Davi.p]

Re: LG55UH615T pulsating Redstanby LED

when you buy new ic801 buy n.2 because i think is bad also in your original board

[wushumike]

Re: LG55UH615T pulsating Redstanby LED

when you buy new ic801 buy n.2 because i think is bad also in your original board

Thanks Davi.p

You have nailed the problem.

Ironically, I repaired the original board instead of the one I purchased. I use the purchased (faulty board) and did some comparison.

So the problem of my original board is as follows:
1. IC 801 faulty ...... internal circuit issue and it also affects the reading of R806 (10K)
2. R822 4R7 value increased
3. While trying to unsolder the MOSFET Q802 5N40, one of the lead drop off , so I cant say if this MOSFET is good or bad....Anyway I don't have this part but replace it with 9N40 which is better spec then the one used.

Replace IC, 2 resistor , 1 MOSFET .... Power Up standalone and no smoke before connecting back to the TV..

All back to normal!!!!

Anyway I didn't bother to repair the CN board.... probably is the same problem as you mentioned.... IC801

Closing this thread.... For those who have same problem, can use this as a troubleshooting reference.

Thanks All who have chipped in for this troubleshooting.

[Davi.p]

Re: LG55UH615T pulsating Redstanby LED

Ok happy to hear it.. bye!

[estrumpf]

Re: LG55UH615T pulsating Redstanby LED

Thanks Davi.p

You have nailed the problem.

Ironically, I repaired the original board instead of the one I purchased. I use the purchased (faulty board) and did some comparison.

So the problem of my original board is as follows:
1. IC 801 faulty ...... internal circuit issue and it also affects the reading of R806 (10K)
2. R822 4R7 value increased
3. While trying to unsolder the MOSFET Q802 5N40, one of the lead drop off , so I cant say if this MOSFET is good or bad....Anyway I don't have this part but replace it with 9N40 which is better spec then the one used.

Replace IC, 2 resistor , 1 MOSFET .... Power Up standalone and no smoke before connecting back to the TV..

All back to normal!!!!

Anyway I didn't bother to repair the CN board.... probably is the same problem as you mentioned.... IC801

Closing this thread.... For those who have same problem, can use this as a troubleshooting reference.

Thanks All who have chipped in for this troubleshooting.

Hello

Plese do you confirme that the resistor next to the 4r7 the 010 is 1 ohm resistor I get 100k value. ????

[lotas]

Re: LG55UH615T pulsating Redstanby LED

Hello

Plese do you confirme that the resistor next to the 4r7 the 010 is 1 ohm resistor I get 100k value. ????

01D - 100 kOm

[alltvrepairs]

Re: LG55UH615T pulsating Redstanby LED

These TVs have a lot of bad backlight issues. Sad part is only 1 led has to go bad for the whole tv to shut down.
Replacing backlights and turning the backlight setting down usually solves the issue. You can also modify the board to lower the amps to the backlights.
There is a thread that describes the process

Hi, bumped into this as have same issue. Have replaced all components mentioned here but 1 channel on pcb defective as TV restarts occassionally. Can you share the link for the modification mentioned please?