I have a HP G62 505sa laptop with the AMD configuration and ATI 4650 graphics GPU in there and it has developed a problem. The screen wjsut decided to cease workign and have jsut got a load of lines accross in (intermittently) wit h pure white background on it..
My first thoughts was its the usual fault with Hps such as an overheated motherbaord GPU.. however, plugged the VGA and the HDMI into monitors and tvs respectively, and it works perfectly with the LED screen disconnected totally from the ribbon. But wen the LED screen is connected along side the HDMi or the VGA out, it doesnt boot at all, shows the screen, keyboard is responsive, but no response from windows.
the cabling condition is not in good condition at all as the main coupling lid has come away from the main gold connector and the connector on the back of the screen is damaged also, leading me to think that its a bad connection to the screen. In short, I know its not the GPU or the baord, so am of the mind that it is a short feed on the LED screen cable. Any other thoughts to back me up on this one?
It looks like your troubleshooting techniques are leading you in the right direction.
It might be a bad LCD data cable (is there a separate power cable?)
It could also be a bad connector on the LCD screen (connector on the back of the screen is damaged).
looking at both, I believe both are affected. Looking at the screen connection, the cable holder is bent outwards possibly causing a short feed on the earth wires to the top of the cable. CAn this be bent back and the screen rescured? Or has the short feed completely done the screen in?