My Screen has gone Grey! Need help Please!

My Macbook (Model number A1278)

My Macbook recently had my LCD replaced by apple due to coloured lines down the left side. Now 4 months later my screen goes to a grey striated colour and can be resolved, sometimes, by pulling on the right top of the screen or by repositioning the screen or putting some torque on the lcd screen.

I have connected the macbook to my HD TV and it works great on the TV.

Not sure if this is a cable problem or if it is the lcd?

Which part needs to be repalced or what is causing this problem??

I added a pic of the screen.