It sounds like the monitor cable. This happened to me with my Dell and they just came out and replaced it
Constantly opening and closing the laptop eventually damages the cable. It will sometimes come on a bootup but as the system warms the cable expands a bit and breaks the circuit. The only fix is a new monitor usually. You could take it to a local computer store and have them fiddle with the cable to see if that works.
No idea why the Acer idiots would replace the HD or memory

... nothing to do with the screen issue
