17" Core 2 with 9400M - quick question

[G.Beard]

Got one of these old 2009 machines here given to me. My tech took it home last night and messaged me to say the screen had gone pixelated. Turned it on at work this morning and it's fine.
Just wondering if it's more likely to be a bad cap or more likely to be bad GPU?

Sure I will test it, but what's your bet?

 

[dukefawks]

Usually the MUX on these, but need to see the actual problem.