Acer Aspire 5580 laptop problem?

Several months ago, my Acer Aspire 5580 laptop screen stopped displaying anything. I figured out everything was working except the screen because when I attached it to external monitor, it worked. Since I find buying a new screen costly and impractical for an old laptop I just decided to attach it to an external monitor permanently, disabling the internal monitor. A week ago, my laptop suddenly hanged. So I just unplugged it and it works again. But afterwards, it hanged again until one day after the hang and unplugging, I tried to open but it doesn't boot properly anymore. The lights turn on and I could hear the fan works, but it won't boot at all. What should I do? Can I still repair it?