LG55UB850V no picture or audio - flashing LED's help please?

[Scoff]

Re: LG55UB850V no picture or audio - flashing LED's help please?

No difference with 3D turned off. Same behaviour with 3D on and off. Does this question relate to R13006 which is for 3D_EN_LGD_120Hz? This resistor is not present on by board, yet the service manual does NOT say it is optional?



Another resistor that the service manual says should be present, but it is not, is R13005 - If I am reading the board numbers correctly? This says Non-LGD 60 Hz T120 module UB85 so perhaps doesn't apply to my board as I do have the T120?

I found a picture online of another EAX65684604 Main Board which also is missing R13018 and R13019



so perhaps some configurations of this board are not supposed to have these 2 resistors, but the service manual has an error and should show OPT next to them...

Either way, they aren't there on my board and never were. I will continue with the freeze test next and see if that reveals anything.

[Diah]

Re: LG55UB850V no picture or audio - flashing LED's help please?

Red arrow side of R13018 and R13019 = 3.272v STABLE
Yellow arrow side of R13018 and R13019 = Fluctuates in time with buzzing, between 3.299v and 3.304v. During each 2 second 'buzz' the voltage climbs from 3.299 up to 3.304v, and when the buzz stops, the voltage falls back down to 3.299v.

we do know S.M are internal documents delivered with other sheets of suggestion and repair steps which we don't have and just we guess issue on MB.
so yes R13018 and R13019 not at MB but they exist at S.M. mean its could be solution or too test way if one of source or gate tap IC pull abnormal currents at panel ( you said ribbon cable contact pins are good. and when you disconnect one a time or both of ribbon the buzzer stop )

so i would put 2 SMD 4.7K in place and see if this rail became stable easy cheep way to try.... if not just remove them.

[Scoff]

Re: LG55UB850V no picture or audio - flashing LED's help please?

I just want to say thanks for all the help on this thread. I've learnt a lot about circuit boards and the general workings of LCD TVs. Unfortunately due to other commitments, I can't spend any more time on this, so will have to store the tv and hope that the correct main board comes up for sale at some point in the future.

[Diah]

Re: LG55UB850V no picture or audio - flashing LED's help please?

I just want to say thanks for all the help on this thread. I've learnt a lot about circuit boards and the general workings of LCD TVs. Unfortunately due to other commitments, I can't spend any more time on this, so will have to store the tv and hope that the correct main board comes up for sale at some point in the future.

sorry MAN. if you were disappointed some how.. the service manual some time issued after the TV in production one years or more.. and we can find MB different version too over all brands. this mean any we find on SM. it could be correction of later version on MB. this i do used before at my work.. its not only TV. this happened always after any new issue appears after using product at end customer . so need to change some parts or add some to solve problem.
if we do know the issued time stamp of S.M will explain its years after 2016.

wish you good luck.

[toke lahti]

Re: LG55UB850V no picture or audio - flashing LED's help please?

WOW,
this was a long thread.

I'm in similiar situation with just entry level skills and equipment.

So maybe this 55UB850V-ZD goes to recycling center...

BUT,
what I'm still curious is, what does those FIVE FLASHES mean?
(Just registered to ask this...)

[toke lahti]

Re: LG55UB850V no picture or audio - flashing LED's help please?

I made a standard bake to my main board 10min 200°C.

And the backlight started to glow!

But, no picture, only vertical magenta lines with constant space between each other.

Anybody recognises this malfunction?
What next?

https://drive.google.com/open?id=16Y...m&usp=drive_fs

[peterkos2]

Re: LG55UB850V no picture or audio - flashing LED's help please?

Hello everyone.
This is a great forum, it always helps me.
This topic also helped me with exactly the same problem. I also lacked 12V power supply to the panel and after warming up the TV started up.
Thanks to everyone

[peterkos2]

Re: LG55UB850V no picture or audio - flashing LED's help please?

Hello. The same TV was returned to me again with the same error, but after warming up the LED LD1900 lights up, but not fully. 12V is missing again on the panel. Didn't anyone solve it already?

[peterkos2]

Re: LG55UB850V no picture or audio - flashing LED's help please?

Hello. The same TV was returned to me again with the same error, but after warming up the LED LD1900 lights up, but not fully. 12V is missing again on the panel. Didn't anyone solve it already?

I also have no voltage on DRV_ON

[krissie]

Re: LG55UB850V no picture or audio - flashing LED's help please?

Hello All, I have a simelar problem. Does anyone have a replacement board for sale or is there an equivalent that will work in this tv?

[ReeceyBurger123]

Re: LG55UB850V no picture or audio - flashing LED's help please?

From my experience with similar boards, seems more like a ceramic capacitor plague developing. In a few common areas they short.

[tjrudd1310@aol.com]

Hi I have the same problem same tv , turned it off then went to turn it on and nothing , I have the same reading on the t-con F1 0.8volts only one led on the main board and the led on the power board flashing 5 times .
has anyone found any main boards or compatible boards yet ? Or a fix for the main board ?

[elviscen]

Hi All,

I have the same problem and no main boards available on the internet.
Anyone have found any solution for this problem?
Maybe re-baling the CPU will work?

Thanks.