Power Supply not working properly after re-insertion

[trenttrubela]

Hi,

I just put my 250W Industry Standard PSU back into my Acer Aspire M5620 Desktop PC.

Once I pressed the power button on my PC, i noticed that 1. I couldn't see anything on my monitor.
And 2. The power button wasn't lit up. Whereas the words "Aspire" on the side of my PC were.
Why would this be?

Note that when I re-applied the PSU back into my PC, I do NOT had P5 and P2 plugged in, could this be my problem?

PS. Please don't call me an idiot for asking this, I'm fairly new to computers.

 

[iam2thecrowe]

i think you havnt plugged something in that should be.