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Old 11-07-2020, 09:25 AM   #1
dominik0801
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Default LG 55EG910V OLED TV clicking

Hi!

I have the TV mentioned in the title. It won't turn on, just click.

I have read many posts here and I tried the TCon/panel test, where I disconnect the motherboard and jumper the PSU on and connect +12V to the Tcon.

The color pattern comes on, and the screen is perfectly fine.

However, connecting the motherboard back, it only clicks again.

I tried a CPU reflow, but the problem remains.

After pressing the power button on the remote, the TV clicks ~ 3 times, then the Stand By LED fades away, like it's turned on. CPU gets warm, no picture on screen, backlight isn't on.
All voltages seem to be fine on the motherboard (I can measure +12, +24, +3.5, +5).
TCon also gets +12V, but only 0.7V on the backlight fuse. But when the PSU is jumped, the backlight also works fine.

I made a jack-IR blaster, POWER_ONLY.wav however doesn't work, checking the IR LED with a camera shows no activity with that wav file. However, opening IN_START.wav makes the IR LED flash.

Any ideas?
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Old 11-08-2020, 07:47 PM   #2
CapLeaker
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Default Re: LG 55EG910V OLED TV clicking

disconnect the wifi module, see what that does.
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Old 11-09-2020, 02:00 PM   #3
dominik0801
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Default Re: LG 55EG910V OLED TV clicking

No luck.. :/

Same happens. I tried a serial-usb board connected to the TV's service output, but it only gives me trash information (boxes, questionmarks) on every baud rates..

Could this be some kind of "protection mode"?
Or maybe the motherboard is dead? And if so, what can go bad on it?
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Old 11-09-2020, 02:04 PM   #4
dominik0801
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Default Re: LG 55EG910V OLED TV clicking

Here are some of the TCON test pattern colors however, so you can see, that the screen and TCON seems to be perfect. Also, since it turns on to play this little test pattern, it means that the PSU should be fine, am I right?
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Old 11-09-2020, 02:35 PM   #5
Diah
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Default Re: LG 55EG910V OLED TV clicking

you have main boards issue.. disconnect yours T-CON and panel from system complete ( LVDS should be disconnected too ) by pass the PSU to turn on Power On Only ( no DRV_ON at this moment ) then feed the MB 12V and follow it if its dropped down . same way of test do it for 24V line on main boards...
BTW yours reflow of the main ic could be did some things wrong too... need to rework BGA to be sure you are at the correct way.
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Old 11-09-2020, 03:18 PM   #6
dominik0801
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Default Re: LG 55EG910V OLED TV clicking

+12V is not dropping, it stays at 11.9 - 12.0V.
+24 is also stable.

CPU gets quite hot to the touch, literally burning my fingers.

I did multiple BGA reflows before and I never had any problems afterwards.
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Old 11-09-2020, 03:45 PM   #7
Diah
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Default Re: LG 55EG910V OLED TV clicking

Quote:
Originally Posted by dominik0801 View Post
+12V is not dropping, it stays at 11.9 - 12.0V.
+24 is also stable.

CPU gets quite hot to the touch, literally burning my fingers.

I did multiple BGA reflows before and I never had any problems afterwards.
at which test its so hot 12 or 24 V test? it cant be both.. let please your answer absolute sure.

this test mean no 3.5V goes to main boards . just to clarify
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