Macbook display issue

Apologies in advance if I've posted in the wrong section- the forum "makeover" is new(to me). I have a Macbook 5,2(2009) that has the blank screen problem, sometimes it does work for a short bit, just long enough to get my hopes up. :-(

Troubleshooting

After removing the bezel around the screen and this piece, I inspected the wires visible at that point. I don't see any pinched or frayed wires, and moving the screen does not cause any change, either way.

I bought and installed a replacement power inverter for the display, and found no difference at all.

So, I either have a bad display, or a failing graphics processor on the logic board- yes?

Any suggestions before I sell this MB for parts will be muchly appreciated.

 

This laptop is still around, but recently I've been revisiting the display issue. Surprisingly, the display has returned, but I'm afraid to move the laptop, as I believe the problem to be a loose or damaged wire.
I think that it is safe for say that:
1. power inverter for the display is O.K., been replaced.
2. the display and back light are O.K.,
3. the graphics processor on the logic board is good.

So, cables or wires... sounds like a drastic tear-down just to check or replace them.

Any words of encouragement, or suggestions?