I have a reasonably old Sony Vaio PCG-FX109K (or FX-190K in USA), it has worked perfectly ever since I got it then suddenly one day it just stopped working. The problem is than when I turn it on I can hear everything working but nothing comes up on the screen (on rare occasions it will boot). When it works it works for about 30mins then just crashes and the picture on the screen turns into weird coloured lines, or it just freezes. I have tried formatting, a new hdd, new ram (all frm another working laptop) and an external screen. I think I might have found the problem. There is a bar just above the keyboard, it has the power button on it, speakers and a few other buttons. When this bar is knocked or moved the whole pc freezes as deascribed above. I have tried a new wire to connect it to the motherboard without success. I'm afraid I don't have a picture of this bar, although if one may help I can istall my phone on my pc and upload a picture. The best i have is this picture.
This is very small but to give an idea it is just below the screen next to the keyboard.
EDIT: Found a picture on ebay here it is: