Cannot turn LG 82UN85006LA TV on, backlight is present
Hi All,
Hoping someone can help me - I’ve been given this LG tv (without a remote) and hoped to fix it by replacing the the Mainboard (which has made no difference).
Currently, as soon as I plug the TV in to the wall - without touching any buttons, the backlights come on and the stand by light blinks 4 times. I do not hear any sound from the speakers, but that may be normal?
I’ve watched a number of Youtube videos that have suggested disconnecting ribbon cables from the T-Con board individually to see if either side of the tv begins to work (which it doesn’t, nothing I do changes the behaviour mentioned earlier). In those videos they go on to tape pins, I have attempted this also with no success.
Can anyone help? I’m considering ordering a T-Con next as it doesn’t seem like a power issue (could absolutely be wrong in this assumption),
Thanks
crwdns2934109:0crwdne2934109:0
@danieldk87 so what I hear you saying is that the moment you connect your TV to power, the backlight turns on and you get a 4 blink error code. Is that correct? You've replaced the main board but have not checked the corresponding voltages on your power board, at the connector where the main bord connects to. Is that correct? A failed T-Con board will not turn your TV on, or prevent it from being turned on. Remember that (simplified) your TV receives the signal to turn on, from the IR-receiver/power button to the main board. It is then that the main board signals the power board to turn every other circuit needed to power on the TV. The power board will essentially provide the standby power to the main board to enable the power-on circuit. Backlight circuit should not be powered at that time. We will need to see your individual circuit boards so we can try and take a closer look. My suspect here is the power bord or even as simple as the IR board
crwdns2934271:0crwdnd2934271:0 oldturkey03 crwdne2934271:0
when you say the backlight comes on does it flash the lg logo and go back off ?
crwdns2934271:0crwdnd2934271:0 daniel crwdne2934271:0
Sorry, I should have mentioned, nothing displays on the screen at any point. It just appears as a illuminated blank screen thanks to the backlights.
crwdns2934271:0crwdnd2934271:0 DanielDK87 crwdne2934271:0
@danieldk87
With LG TVs a 4 blink error code is usually associated with an overheating problem or a software problem.
Given that the TV doesn't fully turn on and the blinking occurs (assuming it does this from a cold start) it seems more likely a software problem - corrupt or incorrect software,
Is the replacement mainboard the exact same model number and version as the original board in the TV?
if it is not exactly the same, try reinserting the original mainboard and then try manually updating the software via USB.
Here's a link that has the software and the instructions.
VERIFY that the FULL model number of the TV shown in the link matches your particular model before trying this.
IF IT ISN'T EXACTLY THE SAME MODEL, locate the software for your exact model.
It needs to be the exact same model to prevent bricking the TV due to incorrect software.
crwdns2934271:0crwdnd2934271:0 jayeff crwdne2934271:0
@jayeff thank you for your input, I’ve just reinstalled the original board. They both appear identical. I have added some photos to the post, as you can see, the model number ends in .BEK not .AEK, but browsing their site the closest I can find is the one you’ve linked, do you think I should go ahead and attempt it with that software?
crwdns2934271:0crwdnd2934271:0 DanielDK87 crwdne2934271:0
crwdns2934273:01crwdne2934273:0