Acer :: Aspire - Turned On, No Display

I started having problems with my laptop weeks ago. First, there were problems with the screen. Sometimes when I turned the computer on, the screen didn't displayed, so I had to try several times for it to come. Then, even when the image appeared, if I moved the laptop a little bit or it was on for a long time, color stripes would appear on the screen.

After that, one day i tried to turn on the computer and a message appeared that said that the operating system could not be found. By then I asked someone at my school and they told me there could be a problem with the hard drive. So I took it with them, and they told me it was so damaged that there was no way to recover the information I had, so I lost all of it. They formatted the drive because in that way there was a possibility I could save the drive even though the information was gone. So the next step was to install Windows XP again.

So I started doing that, but when I turned on the computer, now there wasn't even a message that said that the operating system could not be found. Now there's only this white line flashing on the top of the screen. What can I do now? For what I've read, there can be a problem with the master boot record. Considering that there's a huge chance that my hard drive is really useless now, I was thinking about buying a new one, but I fear that even then I'll still have problems with that boot record.