Blank Screen / no GRUB access after installing Ubuntu 15.04 on Dell PowerEdge 2650

Hello all! I am new to this and am hoping to get some help if possible. I have downloaded the 32 bit version of Ubuntu 15.04 and have installed it on my Dell PowerEdge 2650. The system is set up with 4 hard drives, one as the boot drive and the other 4 as RAID. The install seems to go perfectly, but once the system requires reboot, the screen always goes blank and my monitor says "Input Not Supported". The graphics is running from the on board controller.

I have tried to hold the Left Shift Key, Right Shift Key, ESC, Arrow Down, CTRL+Alt+F1 and still cannot access the GRUB screen I keep reading about. I can see the words "Starting GRUB" or something like that right before the screen goes blank. I have even tried letting the screen go blank, then pressing the arrow down key, then "Enter" and still nothing. Using the install disk, I tried using "nomodeset" as a boot option on the "first disk" which did not work either. With all ideas gone, I am forced to ask for help Anyone have any suggestions on what to try now?