First off, it's not a P.O.S. because it's a DELL. They make quality product and supply most of America with an affordable home-computing solution.
Secondly, there is a good chance you fried the system. If you pulled the plug out while it's on, that's never good. You could try resetting the PSU, but I don't know if that will do the trick.
To do this, follow these steps:
Unplug Power Cord from PC if not already
Hold Power Button on front of case for about 30-45 seconds
There is a red switch on the back near the PSU, flick that back and forth about ten or so times, ending in the same position you started.
Plug it in, give it a shot. Do you get any LED's anywhere on the system? Do you get a blinking amber light on the front panel, anything?