I am experiencing some weird things on my mac mini computer and need some help to solve the issue. For a little while, from time to time, my mac mini is showing strange colors and lines along the screen. Usually I turn it off then after few minutes I will turn it on again and it's alright but this morning it was doing it repeatedly also I wanted to check what is happening if I don't turn it off. So it turn off by itself and on again few times and every time it came on, the colors and lines were back. Until finally I turned it off and left it so for a good few hours. It is working now but I do not know for how long. I do not play games on it, neither surf on unsecure sites on the internet. I am not sure if the problem is with the mac mini or the screen ( I have a 19" HP screen).
I appreciate any suggestion and help,