|3 beeps was caused by bad or incompatible RAM, as you probably already guessed.|
The display problem: If the graphics chip was faulty you would get a beep error code, so it's not that.
Since you aren't getting a beep error code, my guess is either the monitor VGA cable or the monitor itself is faulty, neither of which would trigger a beep error code because they are external components which the BIOS does not monitor.
One last thought - check that power is actually getting to the monitor. The fuse may have blown in the plug on the power supply cable.