I installed a new PSU on my sisters pre 2007 custom built pc. She detected no problems prior to the installation. It is running
Windows XP Home service pack 3. All drivers are as current as they can be, same with any software updates.
I have replaced three other PSU's in other computers and I have never had any problems.
On start up I get a single short beep from bios so I know everything is plugged in the correct slots. Monitor light goes from stand by mode to on then back to stand by within a second or two. The PSU I took out of this pc was a 550 watt the shop gave me a 480 watt. Guy at shop said it didn't make a difference since I had no after market hardware installed. Myself, I like putting back what I took out.
Thank you for any help you can give me.