TV flickers with horizontal lines in 2 second intervals

My Philips TV seems to flicker in horizontal lines that cover the entire screen. During the flickering, the colours are distorted and the image is shifted slightly upwards. It lasts for about 2 seconds at a time, before showing a normal display without any issues for another 2 seconds.

I have tried cutting off the power for some time, as well as checking the connections to sources.

model: 49PUT5801