Is my macbook pro dying? I have a Macbook pro 4,1 early 2008.

It's a great machine for surfing while the TV is on, but it's starting to act strange.





These screenshots are both of a google sheet -- same one a few minutes apart.

I can see two possibilities:

A:  My GPU is dying, and doesn't work in certain modes.

B:  I've got a bad memory stick.

How do I diagnose which?
Run Apple Apple Hardware Test.

Apple Hardware Test (AHT) contains a suite of diagnostics that test the hardware of your Mac.

Here is the official support article by Apple:
https://support.apple.com/en-us/HT201257

And the relevant instructions, "Turn on your Mac, then immediately press and hold the D key on your keyboard. Keep holding the D key until you see the Apple Hardware Test icon."