Dell dimension 5100 power problem

My dell dimension 5100 was running noisy.  It sounded like the front processor fan.  I unplugged it and cleaned out dust from the intake vents then blew some more dust out of the interior.  When I plugged it back in I get nothing but green LED on the motherboard.  No power light at all.  Is this a power supply problem or something else?
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Since you just cleaned it, I would look for any loose connections and whatnot, and try again...

When working inside it is a good idea to unplug the PSU (power supply) and then hold down the power-on button for a few seconds to allow the residual power to bleed out.
What you are describing does sound like a symptom of a failed PSU but you may just have a loose connection.

Make sure the CPU fan is plugged in correctly and if all else fails just lightly wiggle the wires inside the case when you start up...  I have a power supply that I used to do that to, and I don't know why it happened, but I haven't done it for years and same power supply has been working flawlessly ever since.

i agree with the above : first check (= disconnect - inspect - reconnect ) all cables and cards
this can help too :
check for the front panel (power button ,hdd led,system led,reset button ) connection to the motherboard.
dannycamAuthor Commented:
Thank you all for your advice.  I tried turning it on the next morning and it came on and booted up no problem, but was still making fan noise from the power supply.  I took it to my local computer repair store and they confirmed that the power supply was going to fail.  It was replaced and now it works fine.   thank you all,  Dan

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