That, I am sure, will be a video card problem. Extremely difficult to solve with a laptop. But it may be overheating. Do you have the knowledge to open the flap at the bottom and clean the cooing fans and copper cooling tubes?
Fwiw. Why are you running without a battery? "My laptop have no battery it run on the power adapter" That, long term, could have caused the problem. The battery also helps to stabilise the Power, if it develops a slight fault.