If you don't have the money to have it repaired, then you'll need to be qualify to do that repair work.. It's highly possible you've detached some wiring or damaged the motherboard to the point that it needs soldering or replacement of parts.. That's not an easy thing on a motherboard, (impossible if you ask me) and I always choose to replace the board.. First, you can open the case and check to see if any connectors have pulled out of the board.. Reseat them to be sure. Make sure the motherboard is correctly attached to the case.
After that, it becomes a troubleshooting expedition to find the location of the damage.
Hope this helps.
Grif
Last night my PC was moved around with the cords and wires stilattached and this caused the panel that the monitor hooks up to to become detached. I opened up the case and jiggled the panel around until i could take it out and replace it back in its slot. I also lifted up the cover that directs air from the fan and wiped off a large accumulation of dust on one of hte parts.
Now, whenever i plug in the computer it refuses to turn on. I only get a green light on the motherboard and a blinking yellow power light. Is there any way i messed up sometihng in the computer while doing these two things? And if so, what can i do to fix it?
I don't want to pay $500 for geek squad to come out and find some wire that needed the be plugged in

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic