Display doesn't work. Changing screen to a new one do nothing

Hi everyone!

I have a problem with my watch for a while. A month ago my screen starded to flicker with yellow stripes and after couple of seconds it showed nothing. When I’m pressing the button I hear and feel wibrations from the watch, also Google Assistant hear me and speak to me. I thought that the display is damaged so I’ve ordered new one. New display arrived yesterday. I’ve put my watch guts to new frame with display and voila. I’ve press the button, watch is turning on and after about 1 or 2 minutes of joye yellow stripes appeard, screen started to flicker and then it stop showing anything. After that I rotated my watch in difrent directions and for couple of seconds screen starded to flicker and that’s it, dead again. Have you got any idea what’s going on here? What causes this?

Edit:

Strange thing. Last night (I don’t know why) I’ve press the button, and the watch launched perfectly. 5 minutes later screen started to blink and 15 minutes later screen goes off. I try to launch the watch today, I’ve heard and feel vibrations but screen show nothing

Regards

Peter