UE22F5400AK Reboot Loop

[notacake]

I recently bought a UE22F5400AK that's stuck in a reboot loop hoping to fix it. The TV enters standby, but when you try to turn it on the Samsung logo flashes up, then it resets and does it again. Unfortunately I have no idea what caused this, i.e. an update or messing with the service menu, etc.

My first thought was the PSU, but it's an external one and replacing it with a bench PSU doesn't help.

I opened it up and found debug headers for the serial flash and EEPROM next to the Weltrend controller. A logic analyzer shows activity on these lines every time it resets. After looking around on the Wiki and forums I tried the unbrick method by holding SDA high, but that just caused it not to do anything except flash the standby LED (looks like it might be an error pattern: 3 blinks, pause, 2 blinks).

Does anyone know how to fix this? Or at least where the problem might be?

[juusso]

eeprom next to weltrend is sub-eeprom. It`s not related to SoC eeprom which usually causes rebootloops. You want reset it, chech info on wiki https://wiki.samygo.tv/index.php5?title ... M_location
But in general, here are a lot of other reasons to behave TV like yours, e.g. firmware upgrade failure, which is un-repairable ATM.