power up but no boot up

So up until two days ago my pc was working fine but then later that day the pc had frozen after not being used for a certain amount of time. I powered it down then started it back up but then it would start up at all. All the fans were running but it wouldn't boot up. So I unplugged it from the back for a few minutes and it started working again. The next day as soon as a started up the pc it had the same problem. I just unplugged it again and waited a few minutes, then hours, but nothing. I unplugged it from the back and when I plugged back in, it would start up without me pressing the power button in the front, which never happened before. Now I have to hold the power button for around 10 seconds to shut it down but when I turn it on, all fans and the green light on the mobo would come on but the computer itself doesn't boot up at all. Also the USB slots aren't giving out any power at all. I didn't move it, nor bumbed it at all, and I checked inside for loose wires but nothing. It's a Dell with 2.4 intel, 1

Jam it back in, in the dark.

I've had it around for like a year or so. And it powers up but theres nothing but a black screen. Also the little light that blinks rapidly that indicates when its processing/loading only blinks for like one second and stops. I removed a bunch of dust and tighteting wires but nuthing

How ya doing, buddy?

I don't really hear any beeps. I recently moved so there might be the chance i knocked something loose during the move but it's been working fine for like two weeks.and this just randomly happened.
How exactly do i rest the RAM? I'm not a complete noob at pc's but I have personally never done this.

This thing is sticky, and I don't like it. I don't appreciate it.

ok i tried all sorts of things on my own with no results what so ever. I sent my pc to a repair place so that they can diagnose the problem. A week has passed by and they have yet to contact me about anything what so ever. I call them but they say they need more time blah blah.
So I have a simple question, does it really take more than a week simply to examine the damn parts of a pc becuase i really feel these bastards are sorta ditching and dodging around my pc.

I am a dolphin, do you want me on your body?

so it may depend on the pc huh? All i really wanted was a diagnosis, no repairs, so they could tell me what is wrong with it. I thought all they had to do was test out the major components of the pc until they found the problem then I'd just order the part and install it myself since I don't want them to repair it becuase they'll probably just put in some expensive parts and charge me a huge load.

How ya doing, buddy?