Toshiba 55' 55l621u turns on then off - SOLUTION

waterjug · April 20, 2021

This is a very specific issue but I hope this helps someone.

Problem: TV turns on, displays flash screen with logo, then turns off, and a few seconds later the red power light turns off, then TV won't turn back on.

Solution:

If your TV does as stated above, especially if there is a rattling noise when you tilt the TV, or if there are uneven backlight splotches on the splash screen you get a glimpse of, the problem is the LEDs have either failed or are broken. It's not the firmware as other forums have stated, and I initially thought. However, just to be on the safe side now that I've fixed it, I'm not using the built-in smart features, instead using a FireStick, in the off chance a firmware update does brick the TV.

The fix will cost a bit of money and take a bit of time, and the repair isn't the easiest. It will be at a 2-man job at some parts to remove the delicate panel due to the large size of it. Results aren't gaurenteed.

How to fix:

Replacement parts will run you about $60:

https://www.shopjimmy.com/toshiba-4708-k55wdr-a1213k21-4708-k55wdr-a1213k31-a-type-b-type-led-backlight-strips-12/

Tools needed:

-Standard Philips screwdriver

-Mini Philips screwdriver for inner parts (not exactly sure which size)

-Plyers

-Pry tool (credit card or butterknife works)

-Large flat surface

1. Put TV on back on flat surface. Remove feet and back panel. Screws are indicated by small arrows

2. Flip TV. Unscrew Bezel from bottom. Also indicated by small arrows.

BE SURE TO ENSURE ALL HIDDEN SCREWS ARE UNDONE BEFORE ATTEMPTING TO REMOVE SO NOTHING IS BROKEN.

3. Remove screws surrounding screen

4. Unplug panel controllers from board, unscrew panel controllers from metal. Make sure the long circuit boards are above the metal before you remove the screen.

BE CAREFUL OF SMALL PIECES OF WARRANTY TAPE ON LONG CIRCUT BOARD, CUT THEM SO YOU DON'T ACCIDENTALLY BREAK IT WHEN REMOVING IT. THE RIBBONS ARE DELICATE.

4. CAREFULLY lift screen from place. Lay on flat surface. (2 MAN JOB) The long black plastic pieces aren't connected to anything once unscrewed. ENSURE PANEL BENDS AS LITTLE AS POSSIBLE.

5. Plastic light filter layers can be removed.

6. White cardstock needs to be removed, there are a lot of screws.

7. Finally, you are at the LEDs. Plug in the TV to see which ones aren't working.

8. Replace the strip if a LED doesn't work on it. If you bought a full set, replace them all while you're in there. Each LED strip has some screws and a plug. Make sure to take note of which screws you un-did. Be sure to plug in the TV when done replacing and make sure all the leds stay on and not turn off. If they don't turn off immediately when you plug them in, CONGRATUALTIONS, you fixed it. Now time to not fuck up the rest.

9. Put everything back in reverse order it came off. BE EXRTREMELY CAREFUL WHEN PLACING PANEL BACK INTO PLACE, AND DON'T OVERTIGHTEN THE BEZEL. THIS IS HOW THIS REPAIR MOST OFTEN FAILS.

MOST IMPORTANLY, BE CAREFUL, PARTS ARE DELICATE, DON'T FORCE ANYTHING

Once re-assembled, the TV should be working.

If you have the time, feel comfortable enough with doing it, and would rather pay $60 and do this than buy a new TV for a few hundred, here you go.