Randomly on my laptop screen this appears and debian just freezes. Sometimes these vertical lines don’t appear and system freezes anyway. Its just random. How do i identify if this is hardware or software issue? and then how to identify exact piece of hardware or software causing this problem.
have just replugged RAM and lets see if system gets frozen again.
that’s good then! i had this same issue (randomly freezing after turning it om for some time) though new RAM ended up fixing it