2007 Macbook 13" Display grapics help

Bought a macbook to repair, has the following issue (see attachment) screen is grey and whiteish...horizontial lines, sometimes starts to shake but can never see anything on screen.
Tried resetting Nvram, switched lcd cable, anyone think its the gpu? or maybe lcd? Can hear the apple "ding"

Any help greatly appreciated....

When you turn it on, grip the laptop between the left of the trackpad and underneath and see if it still persists.
If it does not still persist then it is a problem with the logic board that I had with my old macbook. Quite a few people had the same problem.
Post back if it works or not and I can help from there.

- Simon

thanks for the help...still persists...