Looks like have one with bad backlight. Here is a diagnostic summary. Will post update after backlight order/replacement and see how easy to get sticky reflector paper off.

Model


Right side backlight failure

This is a white screen test from youtube



LED tester results

Looks like 4x serial circuit. Each circuit is 6 6V LEDs/row x 4 rows or 130V @ 5.4V/LED. A pair of serial circuit is connected in parallel so if only 1 serial circuit fails in this parallel pair causing PSU to safety protection shut off the rail,...

Does main have SPDIF light? when thats on, it usually means main mostly booted okay. Also does main make UI sounds? If so then smarttv OS is running.

I guess check t-con inductors for voltage rails to see if they make sense.

Tried disconnecting left and right panel flex one at a time to see if either 1/2 of the panel has the error? On most Samsungs, require jumper FB_TRDY_1 pin.

https://www.badcaps.net/forum/troubl...el#post3686471

Fixed another one of these with the typical 2x bulging 25v 470uF caps (presumbly the AC to DC bridge rectifier filters). Power section of this all in one board squealed when plugged in. No standby light, no SPDIF light. Changed the 2x 470uF caps (with 35v Chinese caps, we'll see how long this last haha) and TV works.

TV has few other issues:

• Broken coax connector.
• The rubber tape under the edge frame has migrated to become exposed. Peeled and repositioned to original position. Thought about using TESA tape but we'll see how long this holds
• Edge backlight plexiglass diffuser

...

Looks like the reason to the "just dis/reconnect" PSU repair is due to the the PSU backlight connector fingers making poor contact over time (at least for curved TVs) See link

After reassemble the TV, also made a bunch of random clicking and popping noise. Tried adding electrical tape to every screwless rear cover contact surface and didn't help. What fixed it was the following

Can't snap on the screwless rear panel with curved TV facing the flat ground as TV will flex and not all rear cover snap fingers will grab onto each wire properly. Placing something against...

Yes, disconnect MB to turn on backlight is easy. And its a good idea to use this method to keep backlight on while reinstalling all the diffusers to make sure no over bright regions.

I usually like to use LED tester on each LED circuit and read the voltage to confirm LED has failed. Unforunatly caused this connector problem on this style connector...

Just typical LED bar failure repair but discovered a couple of things worthy of posting



PSU had a bulging cap (470uF 25V). Likely AC/DC bridge rectifier filter. Have seen a ton of 470uF bridge rectifier filter failures on a bunch of difference devices (not just TVs) Stock up on 470uF 25v 35v



2nd thing worth of note is after all the work to replace edge lit LEDs. Discovered 2 LEDs with phosphor coating differnce produing slightly differnet color temp. Result on edge lit TV = dark veritical band Can't detect when testing the LED bar along...

Samsung have been using this style LED connector for few years now



Usually good idea to test the LEDs before opening the panel to change them. I do this without the PSU stil connected. With this connector (white one) have to jam the LED tester probes in the very narrow thin slot where the PSU blade style male prong inserts into. I've done this on many Samsungs without problem until today...

The female terminal inside the white connector has fragile fingers that grabs onto the male blades on the PSU's black connector. If the LED tester probe spreads open...

I've done a few of these. Using Samsung Service Manul method always result in some broken bits and the snap lock metal wire always gets bent and not reinstall as nice as original. After reinstall often have some pops and clicks. This is the best method I found so far. Pull the wire out instead

https://youtu.be/paYZAc1rcWs?si=GHdTOv5ySIJgjZOC&t=82

Here is a pic of how the hook on the wire locks



Stil ended up with a couple of small broken bits on the bottom haha. But the wire stayed perfectly straight and seems easier/less forceful. Fishing...