LG55LN575V bad panel?

[Azza111111]

Hi all,

I'm new here, found this forum whilst looking for answers to my latest tv trouble shoot and I'm looking for advice/help with a LG led tv.

I'm hoping it's not the panel at fault but let me know your thoughts?

When turned on the screen lights up and a band of vertical thick lines appears and the slowly makes its way across the screen from one side to the other.

Pressing volume up/down on the remote brings up coloured vertical thick lines down the panel in the area in which the volume is usually shown, same thing for channel up/down ect.

I have no normal picture.

I have tried reseating all cables and visually checking all boards for bad caps ect.

I did disconnect each cable in turn on the tcon but learnt nothing from it really.

I will take some photos later.

Any help would be much appreciated.

Thanks Aaron

[Hamie]

Re: LG55LN575V bad panel?

I've had some strange problems with the mainboard on this TV before (well the 50lnand the 47ln)

Try unhooking half the TCON and see if the image is OK on half the screen.

[Diah]

Re: LG55LN575V bad panel?

sadly things from LG, LN & LM series easily water or cleaning liquid run down on the LCD Tab and make S/C at components .. take look there before you go to change any boards.

[Azza111111]

Re: LG55LN575V bad panel?

Thanks Hamie, Diah,

I will take a look at both of these tomorrow and report back!! Thanks for the tips!

[Azza111111]

Re: LG55LN575V bad panel?

Here are some photos,
The first one is pressing the volume buttons on the remote, the seccond is when I pressed the channel buttons on the remote.

The third and forth are what I see creeping across the screen.

I will do some further tests after work.

Thanks for the advice so far.

[Azza111111]

Re: LG55LN575V bad panel?

I disconnected the tcon board a ribbon cable at a time and these are my photos. Screen still had no images but was more stable, and oddly I have sound after unplugging and really plugging in various connections.

[Azza111111]

Re: LG55LN575V bad panel?

sadly things from LG, LN & LM series easily water or cleaning liquid run down on the LCD Tab and make S/C at components .. take look there before you go to change any boards.

All looks OK here, no sign of water marks or any corrosion, I'm leaning towards buying another main board..

[Diah]

Re: LG55LN575V bad panel?

if you have other TV at home try to connect this LG with scart to other one and check the picture , will it display on the other one good or bad

[Azza111111]

Re: LG55LN575V bad panel?

if you have other TV at home try to connect this LG with scart to other one and check the picture , will it display on the other one good or bad

Hi Diah,

I just get no signal on the 2nd tv, made sure it was in scart source and then cycled through the sources on the faulty lg and nothing was displayed?

[Diah]

Re: LG55LN575V bad panel?

in this case no signal at the other TV, go ahead with replacing the MB.

[Azza111111]

Re: LG55LN575V bad panel?

in this case no signal at the other TV, go ahead with replacing the MB.

Thanks for your help I will track one down, cheers much appreciated!!

[Azza111111]

Re: LG55LN575V bad panel?

Fitted another main board and the problem is the same, had another look and press and check of the bonded ribbon cables to the panel and these are all really good and make no difference to the display when pressed. Could the panel still be bad?

Is it worth me trying a tcon board?

Cheers Aaron

[Diah]

Re: LG55LN575V bad panel?

I just get no signal on the 2nd tv, made sure it was in scart source

scart signal are shared Video / Audio Signal before V. S go to T-CON, and A .S to Amplifier. if yours LG main board ( main IC ) working and give Audio signal then it should with scart connection will be screened to other TV as scart signal receiver

yours LG had Full Scart port . it mean it can send and receive Signal from this Port. you need to try again with this new boards.

[Diah]

Re: LG55LN575V bad panel?

BTW can you post photo to whole Boards on this TV ?

also check the T-CON Fuse ( F1 2A/125V ) read the voltage of it from both side by black probe of yours DMM to GND and the red on F1 pins

[Azza111111]

Re: LG55LN575V bad panel?

BTW can you post photo to whole Boards on this TV ?

also check the T-CON Fuse ( F1 2A/125V ) read the voltage of it from both side by black probe of yours DMM to GND and the red on F1 pins

Thanks for your continued support with this, I've checked the tcon fuse and measuring from ground in dc I have 11v on both sides of the fuse.

I tried the scart test again but can't get anything to to display on the known good tv (checked it's scart with a ver to be sure that works) am I possibly doing something wrong here?

I'm just going to post the board photos ☺

[Azza111111]

Re: LG55LN575V bad panel?

Here we go..

[Diah]

Re: LG55LN575V bad panel?

you need to put RF signal in LG and it should have sound.. then plug the scart to other TV as scart input... it show you the content of the signal.

[CapLeaker]

Re: LG55LN575V bad panel?

What you should have done is to verify the LVDS signal with an oscilloscope, before you got a new main board. Maybe the Tcon is shot.

[Azza111111]

Re: LG55LN575V bad panel?

you need to put RF signal in LG and it should have sound.. then plug the scart to other TV as scart input... it show you the content of the signal.

Sorry I've been a twat, I will connect an aerial and check again later. My bad!

[Azza111111]

Re: LG55LN575V bad panel?

What you should have done is to verify the LVDS signal with an oscilloscope, before you got a new main board. Maybe the Tcon is shot.

Probably beyond my skill set at the moment plus I haven't got one lol.

Not too worried about the other main board I will just sell it on.