Fixed, but What was the Problem?

[Twoboxer]

Recently ran through a debug of what the OP described as:

"My P5Q is boot looping (it seems) whenever I put a graphics card in. I stripped it down to just cpu, memory and graphics card. Without the graphics card I get a short startup beep followed later by 1 long beep followed by 3 short (no vga), but when I plug it in I get one short startup beep followed later by another short startup beep."

Configuration:
Intel Q8300
Asus P5Q
GTX 460
Corsair HX650w

Solution:
Swapped PSU's, vid cards yielded no change. Eventually, the DVI cable was removed and replaced with a DVI-to-VGA adapter, and the monitor's vga port was used. The PC booted up normally.

Question: What kind of monitor/cable failure caused the original symptoms?

 

[johnk10]

a regulation in bios in vga and afterwards regulations from panel the card graphic the hz… etc… download a new drivers of your screen

 

[Twoboxer]

Why did changing the monitor connection to DVI=> VGA Adapter ==> VGA fix the problem?

 

[rolli59]

A short in the cable maybe!