KDL-55W756C stuck in endless reboot. Cannot factory reset or upgrade.

[perisdr]

Hello everyone,

My Sony KDL-55W756C after 5 years of no-issues started rebooting without any reason.

I tried selecting factory reset from Home>Settings>Storage but either the tv would reboot before I was able to reach the menu, or it would stuck in a black screen.

I tried factory resetting by removing the plug and turning it on while keeping the power and volume down buttons on the tv. The led flashes green as per the instructions but then nothing. The tv reboots again, no first time welcome wizard or anything.

The software version is PKG5.435.018EUA. I saw Sony has released a new version PKG5.457.xxxx, so i tried doing updating using a usb. I plugged the usb and the tv started copying the file but when it reached 100% I get a black screen.

Now the TV just keeps rebooting after showing the android nougat loading logo. Before the TV would open for a few minutes before rebooting. I can't even boot in the tv's service menu with the remote.

I am very disappointed, I don't know what else I can try. I can't understand why the TV can't factory reset since the led flashes green. I will probably seek professional help unless anyone else can provide any tips on how I can force the factory reset or the firmware upgrade. Also is it possible to boot into the service menu without using the remote control but the tv buttons?

Thank you in advance for any help.

[Joe_Dohn]

Sadly, your only option here is professional help/engineer inspection since the software update cannot be forced and seems to be failing, and the reset with the green flashes IS the forced reset.

[Mads1984]

Hello friend

You have to change the mainboard. It has somehow got corrupted. 

best/

Mads

[perisdr]

That's exactly what I did. I sent the TV to the service center and they told me that they changed the mainboard. Pretty big damage for a TV of 5 years with normal use.

[HannahEd01]

Hey perisdr, thank you for updating the thread, that's usually a hardware issue as you said. That's due to the nature of the electronics. I make sure to unplug my devices every now and then to avoid that.