LG LED 60LS5750 No Picture but Backlight OK

[handytech]

I have a LG 60LS5750 60" with no picture but backlight/screen works. Could not determine if audio works. Opened up the back and all components seemed to be okay physically. Voltage measurements were taken from cable to main board and to LED driver board. See attachments. Thanks in advance for your assistance.

[tom66]

Re: LG LED 60LS5750 No Picture but Backlight OK

There's a fuse F101 on the T-con board.

Measure the voltage on each end of the fuse relative to the chassis with the TV powered on and in the fault condition.

[handytech]

Re: LG LED 60LS5750 No Picture but Backlight OK

I measured the voltage on the "YD" labeled fuse: 12.23V (left) and 12.23 (right)

[tom66]

Re: LG LED 60LS5750 No Picture but Backlight OK

Do you have an oscilloscope?
If not, I would suggest the t-con first, then possibly the main board.

[caphair]

Re: LG LED 60LS5750 No Picture but Backlight OK

Led backlighting uses an inverter?

[tom66]

Re: LG LED 60LS5750 No Picture but Backlight OK

No inverter, but a high voltage, current limited power supply is necessary.

[handytech]

Re: LG LED 60LS5750 No Picture but Backlight OK

Does anyone have a service manual for this model, LG 60LS5750?

[caphair]

Re: LG LED 60LS5750 No Picture but Backlight OK

No inverter, but a high voltage, current limited power supply is necessary.

Thought LEDs worked off low voltage

[tom66]

Re: LG LED 60LS5750 No Picture but Backlight OK

Lots of them chained in series use a high voltage. Looks to be a little under 160V, judging by that 2.2uF/160V cap.

[Mt.Man]

Re: LG LED 60LS5750 No Picture but Backlight OK

Seen a bunch of these from Costco. Its a bad Tcon board. Part# AGF76630001

[gijoey198079]

Re: LG LED 60LS5750 No Picture but Backlight OK

Any suggestions on where to get the t-con board? I got 2 of these sitting here with the same problem.

[Mt.Man]

Re: LG LED 60LS5750 No Picture but Backlight OK

LG came out with the part number about a month ago. Its a Sharp panel. You can try searching with the Sharp number on the board. But Sharp does not stock the board.
Your only hope most likely will be LG, might be awhile before any LG parts distributor gets it added to there system.

[gijoey198079]

Re: LG LED 60LS5750 No Picture but Backlight OK

Yeah I've contacted both sharp and LG only to come to the same conclusion. I have seen these on ebay with broken screens for $150-$250, may be worth it for this part considering I have maybe $100 in the 2 I have sitting here.

[handytech]

Re: LG LED 60LS5750 No Picture but Backlight OK

Thank you for your info., Mt. Man. I got a used t-con card from ebay and the TV is now up and running.

I would love to find out the malfunctioning component on the t-con card.

[miikeeyyz]

Re: LG LED 60LS5750 No Picture but Backlight OK

http://www.ebay.com/itm/SHARP-PN-E52...item416b154380

would this board work for the same type of TV / issue?

[budm]

Re: LG LED 60LS5750 No Picture but Backlight OK

@MIIKEEYYZ:
T-CON board has to match your LCD panel, you have to match the numbers as printed on the barcode sticker. The same blank circuit board can be stuffed with different component and it will have its own PCB assembly numbers on the barcode sticker for a bunch of LCD panel models. So be careful to match the numbers.

[miikeeyyz]

Re: LG LED 60LS5750 No Picture but Backlight OK

Does anyone happen to know the part number to this t-con board for the 60ls5750, including dashes and whatnot?

[budm]

Re: LG LED 60LS5750 No Picture but Backlight OK

Do you have the picture of this T-CON board of your TV?
The picture on your link to EBAY is not the same T-CON as shown on post1.

[miikeeyyz]

Re: LG LED 60LS5750 No Picture but Backlight OK

I have the exact TV model as the original poster.

So, I would assume that the t-con board would be the same.

[budm]

Re: LG LED 60LS5750 No Picture but Backlight OK

Same model TV can have different LCD panels, panel revision, T-CON revision. As I already indicated, the EBAY T-CON only has one input connectors, the one in the post 1 has TWO input connectors.