PowerEdge T320 with no video

Hello everyone, I recently acquired a PowerEdge T320 that was taken out of service.  The server has been working well in the office with no signs of any failures, it was replaced because it's outdated.  I figured I would throw FreeNAS on it and use it for a home media server.  I tested the machine and it booted fine into the OS right away.  On another machine I downloaded FreeNAS on a thumb drive and removed the side cover of the server and removed the 2 old drives and replaced them with 2 blank new hdd's.  I put the thumb drive in one of the front usb ports on the machine and hit the power button to turn on.  The server seems to come on with the fans spinning and all that but there is no output to the monitor.  It actually makes the monitor come on as if there is a signal but shows no sign of BIOS info or Dell splash screen or anything of that nature.  It's just a black screen. Before I opened the case it had a signal to the monitor and all was working great.  I have no idea what has happened, anyone have idea of things to try?  It's connected via vga, and I have tested the monitor with another machine and it works.  I don't have a lot of knowledge with servers and am stumped.  Also the machine has a diagnostic indicator on the front and it and when powered on the health indicator shows solid blue, indicating it's healthy.  Any help would be appreciated. Thanks!