Lg49uj6200ua

[ljintexas]

Re: Lg49uj6200ua

I have two inbound. Neither one from a cracked screen tv supposedly. I will post results soon.

Thanks

LJ

[ljintexas]

Re: Lg49uj6200ua

Both inbound boards arrived and exhibited the same behavior. Boot up to LG splash screen then goes to setup screen to select language, time zone, etc. Once complete and I select OK, I get a brief white flash then blank screen and no reaction to remote. I tried disconnecting cables to t-con to see if it was somehow displaying setup otherwise..nothing.
SMPS and associated main and signal processing works for info burned onto eprom, not not from other main board inputs. If it was t-con, I would not get LG and setup screens clear as a bell. It has to be the main board.

[ljintexas]

Re: Lg49uj6200ua

HOLD DOWN the power button on tv and while the lights are flashing, start pushing the menu button on the TV at the SAME TIME.

There is only one button on this tv.

[nomoresonys]

Re: Lg49uj6200ua

Ok, must be procedure for different model, wonder if hold down power button and push menu button on remote would work?

[nomoresonys]

Re: Lg49uj6200ua

Thats 5 mainboards right? wonder if theres some common fault with these or its something other than the mainboard?

[nomoresonys]

Re: Lg49uj6200ua

Did you test the tcon at all the test points? guess the tcon could only be partially working?

[nomoresonys]

Re: Lg49uj6200ua

Maybe check the rest of the electrolytic caps of the powerboard, then the blue ceramic caps.

[nomoresonys]

Re: Lg49uj6200ua

Could try heating your powerboard caps a little with a hair dryer, see if it comes on.

[ljintexas]

Re: Lg49uj6200ua

Could try heating your powerboard caps a little with a hair dryer, see if it comes on.

I will try that. I have access to a power supply board. Maybe it can support the low res set up menu and not the full screen video?

[ljintexas]

Re: Lg49uj6200ua

I actually replaced the electrolytic Caps on SMPS..no difference. I tried two more main boards...same thing. I will have an SMPS today. This is very strange.

[nomoresonys]

Re: Lg49uj6200ua

Maybe test the little capacitors on tcon for shorts, diode mode.

[ljintexas]

Re: Lg49uj6200ua

Well today I replaced the smps which made no difference. I have tried six main boards in this set. 5 of them did exactly what is in this video.
{https://drive.google.com/open?id=1qUL6X-nEcmPrf23UDNLq5J4-lN2SIbJ-}
The sixth one made it past this into the setup and would produce audio and video in the PIP screen in the INPUT SELECT tab.
The Tcon is actually two boards that are bonded to the panel ribbons so if one of them is bad, then the panel is bad. hard to believe that five main boards are all bad. All came out of freight damaged sets. One place in Houston says they run them in a set, but they have thousands of boards for hundreds of sets. They have been the easiest to deal with though.

[nomoresonys]

Re: Lg49uj6200ua

Ok, so you can do the initial setup right? try going to picture mode, set it standard and auto brightness to medium or low, turn down backlights to as low as you can stand it, see if it stays on, then maybe you can turn them back up a little if it stabilizes. Do not run tv in vivid mode, its a killer.

[nomoresonys]

Re: Lg49uj6200ua

Theres something odd going on with these tvs, must be a design flaw or they're using components that are not up to the task.

[ljintexas]

Re: Lg49uj6200ua

Ok, so you can do the initial setup right? try going to picture mode, set it standard and auto brightness to medium or low, turn down backlights to as low as you can stand it, see if it stays on, then maybe you can turn them back up a little if it stabilizes. Do not run tv in vivid mode, its a killer.

I never make it that far in the setup, as shown in the video, except with one of the main boards. That one main board will let me into the menu and even display in a PIP mode, whatever is on the input selected..Until I try to go into operation full screen. Then I get the blank screen also as in the video.

[nomoresonys]

Re: Lg49uj6200ua

Ok, can you get to those settings on that board?

[ljintexas]

Re: Lg49uj6200ua

I returned it for credit.

[ljintexas]

Re: Lg49uj6200ua

At this point you need to get known working main board.

I have now tried six main boards and a power supply board. Only other thing connected to the main board is a little interface board for the ON button. I wonder if it could be sending a signal to the main board that it does not like? I am going to replace it to see. There is nothing left but a ton of defective main boards. Hard to believe they are all bad.

[ljintexas]

Re: Lg49uj6200ua

Here is a pic of the button interface board

[budwich]

Re: Lg49uj6200ua

have you looked at the network interface, wifi maybe or ethernet?
If it has a wifi module, try removing it / disconnecting it. If it has an ethernet interface, try connecting to a network and repower.

Have you tried a different remote and / or new batteries?

I don't think you ever answered the "request" to try disconnecting the main board and seeing if the backlights stay on. IF so, did you check the "inv on" voltage signal? Perhaps the one you report (1.85) is low / borderline and when the system goes to "full operation" that value dips.