TCL 50S425 Roku TV Boot Loop

[grimacelord]

Hello again. This time it's a TCL 50S425 Roku TV that is stuck in a boot loop.



The TV will power on, display the TCL logo for a few moments, and then the TV restarts in an endless loop. It sounds to me like corrupt firmware.

So far, I have:

1. Disconnected the power cable and pressed and held the power button down for 30 seconds and tried powering on again - No change.

2. Pressed and held the RESET button for up to 60 seconds. - No change.

3. Tried disconnecting power cable in the middle of one of it's loops, as suggested by dozens of Reddit and TCL support threads. - No change.

So here is where I have tried to create a USB to manually update the firmware via the USB port.

I went to https://tvupdate.roku.com/index?p=select and began to follow the prompts. I choose TCL as the brand and enter 50S425 as the model and enter the SN found on a sticker on the back of the TV.

After submitting my information about the TV, I get an error message saying that it's an invalid model number. "Roku Model Number is 4 numbers and a letter" and then proceeds to tell me to use the remote to go to Settings ---> About ---> and find the "Roku Model Number". This is my problem. The TV doesn't boot. I CAN'T get into settings to get that model number. All I have to go on is what is printed on the stickers on the back of the TV or the mainboard itself.

Attached are a couple of photos of what is actually printed on the back of the TV. I was hoping someone could help me figure out the "four letters and 1 number" of the "Roku model number" they want so I can download the firmware and try manually updating via USB to see if this fixes my issue.

I was even going to go as far as dump the firmware from the mainboard and read it in a hex editor to see if I could get this model number they want (or even manually flash the firmware directly using a programmer if USB doesn't work), but it looks like it's stored on a NAND flash chip and I don't have the proper programmer to read it.

So anyway, can someone help me figure out what model number they want? It's going to be embarrassing if it's super easy to determine and is right in front of me all along.

[gavric]

Originally Posted by grimacelord

Hello again. This time it's a TCL 50S425 Roku TV that is stuck in a boot loop.



The TV will power on, display the TCL logo for a few moments, and then the TV restarts in an endless loop. It sounds to me like corrupt firmware.

So far, I have:

1. Disconnected the power cable and pressed and held the power button down for 30 seconds and tried powering on again - No change.

2. Pressed and held the RESET button for up to 60 seconds. - No change.

3. Tried disconnecting power cable in the middle of one of it's loops, as suggested by dozens of Reddit and TCL support threads. - No change.

So here is where I have tried to create a USB to manually update the firmware via the USB port.

I went to https://tvupdate.roku.com/index?p=select and began to follow the prompts. I choose TCL as the brand and enter 50S425 as the model and enter the SN found on a sticker on the back of the TV.

After submitting my information about the TV, I get an error message saying that it's an invalid model number. "Roku Model Number is 4 numbers and a letter" and then proceeds to tell me to use the remote to go to Settings ---> About ---> and find the "Roku Model Number". This is my problem. The TV doesn't boot. I CAN'T get into settings to get that model number. All I have to go on is what is printed on the stickers on the back of the TV or the mainboard itself.

Attached are a couple of photos of what is actually printed on the back of the TV. I was hoping someone could help me figure out the "four letters and 1 number" of the "Roku model number" they want so I can download the firmware and try manually updating via USB to see if this fixes my issue.

I was even going to go as far as dump the firmware from the mainboard and read it in a hex editor to see if I could get this model number they want (or even manually flash the firmware directly using a programmer if USB doesn't work), but it looks like it's stored on a NAND flash chip and I don't have the proper programmer to read it.

So anyway, can someone help me figure out what model number they want? It's going to be embarrassing if it's super easy to determine and is right in front of me all along.

I had tv like this, it was hisense, about same as tlc. It was acting like it could not go past TV brand logo. It turned out it was bad capacitor on the screen buffer board that was heating up in like 2-3 seconds and causing the short. I found it by taking tv apart and then going and looking at these buffer boards that are attached to the screen. Actual small surface mount capacitor would get so hot that it would melt solder and all this in 2-3 seconds and then solder would cool and all over boot process every 5 or so seconds. I simply removed this little capacitor and tv worked, there was like 5-6 capacitors all connected parallels and i guess one of them went bad.

Open the tv and disconnect tcon board from main board and if tv stays on you are having same issue. You will know if tv is on by You can hear clicks if you try to turn volume up or press menu buttons on remote.