Re: TCL 65S517 No Backlight, Picture and Sound OK

So good news and bad news.

Good news: The 65S517 does not need to have the LCD removed to access the backlight LED strips. This is an edge lit panel and the two strips are on a detachable metal bar on the bottom.

I removed this and tested the strips. Each and every LED lit up nice, bright and consistent with all of the other LEDs. Well, that's strange. So I re-connect the strips to the TV and power it on. The strips light up and remain lit up the entire time. WTH? This is using all of the original parts....

Re: TCL 65S517 No Backlight, Picture and Sound OK

I did that test. Had no voltage but hoped it was due to a bad chip on the power board. Turns out it was not the power board. I got a new one and it didn't fix the problem. So it has to be one or more bad LEDs.

I just bought a new Samsung 70" to replace this one. On the fence about trying to repair this TCL or not. Part of me wants to give it a shot for the heck of it. Also considering selling it as "needs repair" or for spare parts. Seems a shame to throw it out when everything but the backlighting is...

Re: TCL 65S517 No Backlight, Picture and Sound OK

I tested all of the connector pins and the OZ IC voltages on and off. I get the exact same readings as OP. Same behavior as well, where it lights the backlights for milliseconds, then immediately shuts them off. I'm hoping the OZ chip is bad or perhaps one of the components supporting it.

With the LED connector unplugged, the PSU still does not supply power to the LED connector, expect for a brief moment. I've seen in a YT video that when LEDs are bad, unplugging them from the PSU should allow the PSU to output the voltage...

Re: TCL 65S517 No Backlight, Picture and Sound OK

I have the same model as rebelkustoms and it's doing the same thing. When I reset the set, the backlight will flicker for a split second, two times, every time. So it's not dead. I bought a 'Jeston' LED tester and have read each of the 4 strips. They all read the same. The readings start at 164, then after a few seconds the reading increases to between 169 and 171. Every strip reads exactly the same so, I'm reluctant to disassemble the screen because these readings indicate to me that the LEDs are likely okay.

The BL_EN...