Power mac G5 turns on but will not boot up

Hello,

I have the last power mac G5 quad core made before apple switched over to intel. I have not used he computer in about 3 month and it worked fine when I put it into storage but when I tried to turn it on today it will not boot up.

There is constantly a yellow light on near to where the RAM snaps in even when the computer is off. (this is the 3rd light up from the bottom and the only on that is on at this point)

When I press the power button a red light turns on for about one second. Next to this light are the words LED806 Checkstop and it is offset to the right of the other lights a little bit when looking into the side panel of the computer. This light also lights up briefly when I press the power button to turn off the computer.

After pressing the power button another red light turns on just above the yellow light that is always on and the screen is still black. Then the screen eventually turns grey with the apple logo as it normally looks except some of the pixels are off colored a bit in square patterns across the screen. When this happens a green light turns on just below the yellow light. Now there are three lights on all at once.

Next the screen briefly turns light blue and then a little darker shade of blue and the computer will not boot up or go any further than this point.

Can anybody tell me what is going on here and is there any way to fix this?

Is there any way to reset or reboot the computer this the install disk?

Distortion on the startup screen (hard to see in this photo)