Computer wont boot. comp wont boot when it does if you move laptop, screen goes black then trys to

Question

comp wont boot when it does if you move laptop, screen goes black then trys to restart or freezes up nothing functions fan stops spinning wen frozen up wen black screen fan spinning tried swopping memory. harddrive its as though something loose ? could anyone help or had same problem the laptop out of warranty by month or so does anybody think faults on motherboard and if it is were could i get one ? thanks