Macbook Pro 17" 2.4 Core 2 Duo Intermittent screen fault

Have an issue with my old core 2 duo laptop

Sometimes the screen goes psychadelic..... its not the usual failed GFX type of issue as its more like the colours are confused.
When it happens it can be cured by moving the laptop screen slightly or squeezing the lower case in just the right place. The issue never appears when its connected to an external screen.

I'm thinking its the display cable from the mainboard to the LCD that's the problem.
Before I spend any cash, does anyone have any other thoughts as to what it could be?

I know the laptop is quite old but It's been good to me and it still does everything I want it to without a fuss

You're probably correct in that it's either a loose video cable connection or perhaps a brittle cable that's intermittent. Go to iFixit: The free repair manual and look up the take apart instructions for your MBP. If you feel up to it, take it apart and check the cables.

Thanks, can pick up a cable for 25€ delivered so I'll give it a bash