I have looked around the forums and found various people with the same issue, tried a bunch of the fixes I have come across to no avail. Any other potential fixes had dead links so I wasn't able to try those. I've read that a mainboard replacement can be the fix if all else fails so I wanted to run by everything I've done and how it has behaved, as I've had some strange results, before purchasing the replacement part.

So firstly the description of the issue. I bought the TV used off someone who claims they updated the firmware and the TV will boot up, do the android logo then the screen goes black, displays it's on the hdmi source then immediately reboots to the same cycle. I googled and noticed this is a common issue.

What I have tried:

• Factory Reset - Hold vol- and power button while plugging the power socket back in and wait till the light goes green, let go and the setup screen should show up to perform a factory reset. The light goes green for about 5 seconds then the TV restarts back to the previous boot cycle.
• Safe Mode - Hold vol- down when the google/android logo shows and then safe mode will appear down the bottom left. This works successfully and the TV will get to the previous hdmi screen and stay there long enough to state there's no display connected. So I connected my nintendo switch and I get a picture and can navigate the menus within the switch and turn the volume up and down on the TV but after about a 30 seconds to a minute the TV restarts back to the previous cycle.
• Firmware Update via USB - As the issue arose from a firmware update I figured I'd download the latest firmware and try and manually install it. If I just insert the USB stick into the TV and let it turn on it changes the boot loop, this time instead of making it all the way to hdmi source it'll freeze as the android logo is being displayed then reboot. So I tried entering safe mode and doing the same thing. What happens here is once the USB is recognized it'll start to load up the software I believe as the google/android logo starts up for a split second and then the TV reboots again.

I want confirmation a mainboard replacement may fix this or any insight into what else I could try if it is strictly a software issue or insight into if it may be another hardware issue. I'm comfortable replacing any part but I just don't know how to narrow down the issue further except knowing that it's related to the software as it will boot and work in safemode for a little while,

Thanks