I am resurrecting this post because I am going through this same thing and also I have a tip to add. I likewise have a 55" Hisense bezel-less that I trash picked last week. Of course it needs backlights, don't they all? 🙄

I did this same repair on a Toshiba earlier this year and while it went seemingly smooth, after selling the tv and the customer wall mounting it, the tape wasn't holding well so the panel sagged and damaged the bottom corners rendering it useless. I did use 3M double sided electronics foam mounting tape. I DID NOT however, use adhesion promotor or tape primer....

Yes, and I only got around to doing anything with the tv Saturday night 😂 most of my communication on here is while I'm away from home and so I gather ideas and put them all into practice whichever night of the week I'm back in front of the tv....

I got my service remote today. However, last night I decided to clean all of the ribbons with alcohol and afterwards the image appeared much better and the brightness control is now working properly. I noticed it looks exceptionally well with certain content but not so much with other content. It looks like an auto dimming feature, and I did notice the settings automatically change based on the content. I've read about LGs having certain undesirable features that you can only disable in the service menu. Is there anything I should change or disable considering I have this new remote?

I do not have one, but I could order one from Amazon if necessary.

Edit: I just ordered a service remote. It should come tomorrow. What should I do when I get it?...

I did a color test video from YouTube last week and recorded it. I've attached it....

Check out the attached photo and video and see if you still suggest it's backlights. I know what you're talking about in the first post, but in general everything is just less bright than it should be. Plus I don't think blueing of the backlights would do the settings from working properly, but I could be wrong....

I have a multimeter. Are you thinking one or more of those 6 caps are bad?...

I put a heater on the power supply and got the caps nice and hot. No change in image brightness, nor the ability to increase/decrease brightness. It's odd that Backlight will change according to where I set it (0-100), but brightness doesn't change a lick. It looks the same at 0 as it does 100. There's gotta be a failure somewhere on the main board.

That's a great idea. I don't own a bet l blow dryer bit I do have a hot air station. What would be a safe temperature and distance for this application?...

Does anyone have any suggestions? After doing some more research on not being able to adjust brightness z on other tvs, I'm really leaning toward this being a bad main board. If I knew what to look for and could confirm then I'd go ahead and order a replacement....

I checked the voltage at the backlights plug last night and it was 123v. Then I unplugged it and put my backlights tester leads on the wires and got 120v there. So it's safe to say the backlights are getting the proper voltage. I then factory reset the tv and went through the setup again. I found something interesting when playing with the settings. Some things make absolutely no difference no matter what I set them at. Brightness for example, had no effect. The screen looks the same at 0 as it does at 100. Tint was another that had no difference from 0 to 100. I did find that if I manually crank...

nomoresonys
I did try all of the picture modes and even cranked the brightness to 100 on top of backlight at 100. I did not try a factory reset though, but the firmware did update and there was no change after.

Diah
I am going to pull the back off tomorrow and look at the power supply. It really does seem like a low voltage scenario. I'm also going to check the voltage at the backlight plug and then disconnect them and put my tester on then to see if they draw the same voltage....

So I've got this 55UP7000PUA that has a very washed out and dim image. I've played with all of the settings, turned brightness to 100 as well as panel backlight, made sure no eco settings are on, etc. It looks like the backlight is at 50% or even less. I've been reading online that this is a pretty bad model with poor contrast and image retention issues, but I haven't seen anyone say it's dim like this. I've seen quite a few LGs with bad backlights before and they are usually blue. This doesn't appear blue, just washed out and dim. I've likewise never seen ANY backlights simply dim as a failure....

I will check that out. I did try to disconnect one at a time and each will display a solid white side while the other has that strive effect. I did not have anything jumped tho, so I'll look into that....

I have this un50M5300AFXZA that's exhibiting some strange behavior. When powered on it displays white with some horizontal lines, then goes to a vertical strobing from the center of the screen to each side. I've never seen something like this before, but I'm thinking it could be the tcon or main board. The behavior and patterns are consistent across both sides of the screen, so I don't think it's a panel issue but I could be wrong....