Used computer shows nothing on the screen when booted

Spiffy123

Honorable
Aug 8, 2013
1
0
10,510
I have a 5 year old computer from my friend's company. Before they disposed of it, they took out the hard drive and battery. I have since replaced those but nothing comes up on the monitor when I try to boot up. What else could they have removed that is preventing the monitor from posting on start up?