What are the circles on the screen?

Hi Alex,

I'm hoping some of our members who have more expertise in television repair than I do can chime in here, but in the meantime I'll give you my best guess.

Frankly, it looks to me like the pattern of LEDs used as the backlighting for the LCD screen. If you look carefully there's a regular pattern of rows and columns to these circles that I'm sure correspond to the positions of the backlight LED strips.

So I believe that what you're seeing is a set of LEDs that have dimmed over time and no longer project a bright enough light to cover the entire area they're supposed to light up; instead you're seeing a smaller circle of light and the dim area is the space that the faulty LED isn't covering that it should.

My guess would be that you will probably need to replace the backlight LEDs. it you're handy with basic tools it's definitely a doable do-it-yourself repair, but you have to be very careful with the LCD panel to avoid damage when you remove it.

There's a company called ShopJimmy that seems to specialize in flat screen television repairs and parts, and while they don't seem to have a video on your exact model, they do have one that goes through the process on another LG 55" TV, so that should give you a good idea of what you'd be getting into if you decide you want to give it a go.

TCL 55" TV LED Strip Replacement Tutorial for TCL Models 55S401 & 55S405 - YouTube

It appears that they normally sell the LED strips for your specific TV, but they seem to be out of stock at the moment. You can, of course, try other sources such as eBay, Amazon and independent TV parts companies, but here's their page on your LEDs.

TCL 006-P1K3525B/006-P1K3542A LED Backlight Strips (12)

As I mentioned, there are a lot of people on here that are smarter than me with regard to flat panel large screen televisions, so hopefully you'll get some suggestions of things to try or check before you dive right in and replace the backlight strips.

Hope this helps; let us know how it goes!