Hi my laptop keeps shutting off or getting stuck while on it. I use to get a message system your cooling system not working but did a system restore so that doesn't come up. on the back of my laptop it does feel hot I let a tech look at it today and he used a compressed air and he sprayed the fan and computer . he said he see's no dust , corrosion , or damage to the laptop. and gave it back to me so far it didn't shut off yet but the computer is still hot and feel like it will again. Anything else it could be or any advice on how fix this problem?