I am trying to fix a MacBook Pro (one of the earliest Intel processor models) that spontaneously gets into a state where stripes would appear in a checkerboard pattern all over the display. Please see attached image:

I can't find anything trigger for this phenomenon, occasionally it appears during the startup process when the grey Apple logo appears.
When it occurs, the display is frozen and I can't do any work. However, the computer itself seems to still function, because I can press then power button followed by Return, and the computer will turn off.
I suspect this is a hardware problem, one that is hard to fix because this model is so old with no warranty for years. But I would appreciate any ideas on how I may fix it before I give up. Thank you.