Computer won't start

[Aiya]

I built a computer in September of last year and everything has been running perfectly on it until today. I opened the case to clean out some of the dust using a microfiber rag on the case only and dust off spray. I put it back together and replugged everything back in and it won't turn on at all. When I hit the power button nothing at all happens. No fans, lights - absolutely nothing. Here is what I have tried so far:

I made sure that my computer was in fact plugged in and turned on - even tried plugging into the wall outlet both with the original cord and with a duplicate cord

I ensured that all of the power supply wires are plugged in securely and properly both into the psu (modular) and the motherboard and hardware

I tried to turn it on shorting the power pins instead of just the power switch

I tried swapping the psu out with an identical model (I reused the actual wires as it is modular with the exception of the mobo & cpu plug as they are attached to the psu) I didn't want to unplug everything but it is looking like I might need to

The only other thing to note is when I plug everything back in my mouse does light up like it is getting power

If anyone can tell me what my next steps should be that would be wonderful. I have $1000 worth of parts less than six months old sitting in front of me and I have no idea what went wrong.

Thank you!!

 

[MotherFerJones]

Before going straight to breadboarding the system, go ahead and reset the CMOS, either by using the switch on the mobo if there is one, or removing the battery for long enough. If that is a no go, then go ahead and breadboard the system, it may be a pain but it'll tell you where your problem lies.

 

[Aiya]

Three words:

I LOVE YOU!!

That completely fixed it and it is back to running like a champ. I was about to really freak out. This was my first build ever. I am so glad it was something so simple. May I ask what happened and why this fixed it or is it just like rebooting windows, it just does?

Thank you! Thank you! Thank you!

 

[Aiya]

Best answer selected by Aiya.

 

[MotherFerJones]

First, your welcome, and thanks for BA. When i read that you couldn't short it with the I/O pins on the mobo, i figured your mobo had gone retarded, and yes that is the technical term lol, so then i figured before you do anything else the CMOS could use a reset, so thats what i throw out there. Its hard to put into words my thought process, but thats pretty damn close.