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.
for context, i have been using debian 12 for last 6 months perfectly fine. Its just from last week my laptop is randomly freezing and then I have to hard reset it everytime this happens, (pressing power off button for few seconds to force shutdown).