Samsung TV LA46B550K1R flickering issue, so near yet so far

[Indie]

Hi,

I have a samsung tv (2009, works well) apart from an imminent flickering issue for some time.

Model: LA46B550K1R
Model code : LA46B550K1RLXL
Ac:100-260 V 50-60Hz, 240W
Power supply circuit: BN44-00265B

I read through the forums and found other Samsung models both 46, 55 inches , old and new with similar issues. Two things stood out:
1. eco setting in tv was recommended to be switched off
2. Jumper number JP852 was recommended to be cut off.

Now before opening the tv i tried playing around with the backlight since eco setting was already turned off for me. I must say at this moment that everything else in the tv works fine apart from the flickering(intermittent).

So i reduced the backlight from 9 to a 5 and also performed a reset in the settings (reset also puts it back to 5). This stopped the flickering for close to 24 hrs. When i switched on the tv today, i found this issue again while watching , intermittent. So it flicks for a few minutes and then goes away, back to normal.


So i gave in and thought of opening the tv unit (to solve the problem once and for all) and locating the jumper above. Now, nowhere is my model number or power supply circuit number(both mentioned above) mentioned in the forums , hence the jumper jp852 was not found in the same location as in the videos or diagrams.

I shall attach pictures of the board herewith. So after a while i located the jp582 but it is next to the two black capacitors on bottom right. Where it says 46 inches, i was confused as there were many JP numbers.

1. So my query is which jumper should i cut so that this flickering stops.

I presume this particular tv model might use a different jumper number than the 582 for the said function. I may mot be able to replace the resistors so while i know this “cutting” will play withe protection circuit, i am ok to go ahead provided i am sure that i am cutting the right jumper.

2. Also, what are the risks i am undertaking while doing this from a protection point of view?

Plz help as i have opened the tv and would like to solve this today itself.

Many Thanks

[budm]

Re: Samsung TV LA46B550K1R flickering issue, so near yet so far

Cutting jumper is not real solution, all it did was disconnecting the LOW PFC boost Voltage protection circuit, the problem is low PFC boosted Voltage due to resistor network in the PFC Voltage feedback circuit, the resistors have drifted off value.
You can check the PFC boosted Voltage to see if it is within 380 ~ 400VDC or not.

[Indie]

Re: Samsung TV LA46B550K1R flickering issue, so near yet so far

Cutting jumper is not real solution, all it did was disconnecting the LOW PFC boost Voltage protection circuit, the problem is low PFC boosted Voltage due to resistor network in the PFC Voltage feedback circuit, the resistors have drifted off value.
You can check the PFC boosted Voltage to see if it is within 380 ~ 400VDC or not.

Thanks budm. Not sure if i know how to do it. Can you plz help me with the steps and also, what needs to be done post the check.
Appreciate it.

[budm]

Re: Samsung TV LA46B550K1R flickering issue, so near yet so far

Thanks budm. Not sure if i know how to do it. Can you plz help me with the steps and also, what needs to be done post the check.
Appreciate it.

You will put your DC Volt meter's probes on each leg of cap CP803 (100uF 450VDC), the Voltage should be between 380 ~ 400Vdc when TV is turned on, you must be real careful since you are making measurement in the hot deadly side of the circuit so do not touch any thing with your hands.
BTW, the cut jumper is not applied to this BN44-00265B.