My laptop screen fades to grey while in use on a r...

My laptop screen fades to grey while in use on a reoccurring basis. Took it to the Wallingford PCW who then sent it to the Orange branch. They diagnosed the problem as a faulty screen. I paid them to replace the screen. It did not correct the problem. Took the computer back to them. They then said it was the LCD cable. 4 weeks later I get the laptop back and the problem remains the same. The screen still fades to grey while in use on a reoccurring basis. In addition, there is NO communication between the Orange & Wallingford branches. I had to hound them to get information about what was being done and why it was taking so long.