Decided to stop working and is stuck in boot loop. Powers on and can hear Samsung welcome sound, which gets cut after 2 seconds and tv reboots. Nothing shows on screen.

Steps taken: Inspected power supply and don’t see any swollen capacitors. When disconnecting main board from power supply, led backlight stays on. If leaving the main board connected to power supply but disconnecting the ribbon cable to panel, again can hear the sound and no boot loop. Was playing around leaving one ribbon cable plugged in out of two and there is nothing showing on display however tv is not stuck in boot loop. If there was a tcon board I would assume it was at fault, however on this model seems like tcon is integrated in main board.

Am I right in thinking issue is main board ? If board would be fine, leaving one of the two panel ribbon cables plugged in should at least show half the screen right ?

Anything else you would advise to check before I go and try to order new main board ?