dim backlight and flicker

[Brucetafer]

I have a UN65F6350AF that was given to me with a weird backlight issue. the voltage is ramping and my power supply died so I can't test the LED's at the moment.. picture is fine, so its a backlight issue.. Im hoping its not dead LEDS because the frame is one big sticker on this one for the light surround stuff.. any help would rock.. once I fix this one i have a 8000 series with vertical lines and a dead power supply that hopefully is fixable..

[Andrew F. Ali]

Re: dim backlight and flicker

Looks like bad LEDs to me.

[budm]

Re: dim backlight and flicker

You have 3 LED stings and if you look at the Voltage chart, you will see the Voltage rating printed on the board.
Power supply board: Leave the meter probes on C9102 legs then turn on teh TV and see how high the Voltage jumps up to and then wait 10 seconds to see how low it goes down to the turn off the TV and repeat the same test on C9202, C9302. Report the results.

[Brucetafer]

Re: dim backlight and flicker

9102 is going from 320-360 jumping all over 9202 is doing the same, and 9302 is solid 195v

[budm]

Re: dim backlight and flicker

So how much is the C9202 showing?
Next, disconnect the LED connector and do the same test again.
So far it looks like you have two bad LED strings.

[Brucetafer]

Re: dim backlight and flicker

9202 is showing the same voltage at 9102, 320-365ish jumping ill do the voltage test now.

[Brucetafer]

Re: dim backlight and flicker

unplugged is doing the same on all 3 now, 320-365v jumping

[budm]

Re: dim backlight and flicker

I expect the Voltage to jump up high with no load, so at this point you do have Bad LED/or bad connection in the LED strings.

[Brucetafer]

Re: dim backlight and flicker

well this sucks lol.. thats a TON of LEDS... not easy to test at all.. any tips on where to start?

[budm]

Re: dim backlight and flicker

Something like need to you need to use LED tester so you can test each LED strip first to narrow down as to which strips are not working, right now you only have one working LED string that is why you see bright section in the middle of the screen in your post 1 picture.
Also look really close at the LED LENS to see if any of show brown tint due to LED over heated.

[Brucetafer]

Re: dim backlight and flicker

gotcha, that one strip that melted the hole, what are those little chips? my new power supply just showed up so now i can start testing again..

[Brucetafer]

Re: dim backlight and flicker

ok just got my new power supply and snagged a sweet scope for cheap, looks like i have 3 strips that are toast, now finding replacements are not easy for some reason, anybody have a recommendation on where to find them??

[budm]

Re: dim backlight and flicker

There are P/N printed on the LED strips.