From the symptoms you decribe it seems it could be one of three things wrong with the machine.
1) screen cable faulty (if you open and close the screen it is likely to flicker)
2) screen itself may have a fault ie the PCB board where the screen cable connects.
3) fault with a connection on the motherboard.
I have found a company who carry out repairs at a very competative price and deploy a no fix no fee sceme so theres nothing to lose. I have provided a link to their site below.
http://www.laptoprepairspecialist.co.uk
