Build will not boot

[schauera30]

Hey guys I have a problem with my build. Recently i received a bigger case to move all tbe parts of my xps 8500 into. The como uter worked fine before I started moving around into the new case. Last night I got it to power up in the case but there was a rattling noise coming from the cpu fan. I decided that 2 in the morning was a bit lare so I turned off psu unplugged and went to sleep. This morning however it simply won't boot. The orange mobo light turns on and fans spin for a few seconds then stop. I'm wondering what could be wrong because none of the equipment is faulty. Could that rattling earlier be the problem?

 

[schauera30]

Also to add a few things the first time I found a standoff shorting out the mobo but after awhile the problems came back. I paper clip tested the psu and it works but with connections to only the mobo cpu and fan abd ram it will spin the fan for a few seconds before shutting off again

 

[Kisianik]

I hope you still have the old case.
There is a problem with connectors.
New case model please?
Have you connected all PSU connectors, including 4 pin?
I suspect on/off switch connector, Dell might have proprietary wiring, need a lot of time to investigate.
Another question, get image hosting site - you will have to make pictures and post them here.
I will help, but it will take time to solve it.