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.

How old is the computer?
When it is starting up(and failing) do you see anything on-screen(like BIOS version, etc), or does it remain perpetually black throughout the process?

There's nowhere I can't reach.

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?

Hmm... do you hear any beeps? If so, how many?

I suspect it might be either the PSU or the motherboard.

How ya doing, buddy?

Try reseating the RAM. Commonly that can cause a computer to freeze or display BSOD errors, but sometimes it will prevent the computer from posting.

I was speaking idiomatically.

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.

What kind of toxic man-thing is happening now?

There are two tabs on either end of each stick that hold it in. Pull them back and the RAM will pop out. By all means, inspect the RAM for anything that might be faulty, but odds are they will look fine. Press firmly to get the RAM back in, making sure said tabs are back in place. You should do this on a table and off carpet to reduce the chance of any accidental electrostatic shocks.

FELIPE NO

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.

What, you don't want my bikini-clad body?

If you sent to Geek Squad, good luck with that.

It really depends on how much they have waiting queue. If they are going to do an intensive test, they'd lay everything on a test bench and swap components until they isolated the problematic component(s). If they had those parts on hand, which they should, I'd say it would take around an hour or so.

Most amazing jew boots

Well, it depends too.

I presume your computer isn't on some sort of replacement plan. I remember giving mine to Circuit City with the instructions of 'I need this in a month'. We kept calling and they kept saying they were still 'testing'. Truth was though that they probably realized they couldn't fix the problem and were trying their hardest to avoid having to refund my money.

Oh, and there was no queue at that time...

There's nowhere I can't reach.

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?

Generally they aren't going to buy the most expensive part out there. They don't get a profit most likely. They get their money from rummaging through it and figuring out the problem.

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