Sounds like your mobo crapped out on you.

ftp://ftp.abitshop.com/pub//manual/english/fatal1ty-an8-sli.zip

That's a link to the manual for your mobo. POST definitions are at the very end (see appendix G)

Don't forget to switch your CMOS jumper to CLEAR for a minute then back. Sounds hardware related. Try totally different RAM sticks, obvioulsy making sure whatever you put in is compatable.

Your motherboard is probably cracked. Very common with notebooks. Turn it off, press down on your keyboard area a couple times (not too hard), turn it on. If it still wont' work, turn it off, and...

With a notebook? Not really. You'd have to take it to a specialist or some kind of repair shop. Send it back to the manufacturer would probably be best

You'll need to check the manual for the motherboard to understand what those beeps mean. Each is different.

Could be a number of things. Faulty power supply, CPU, really anything - what do you have in it, when did it work last, and what did you do to make it stop working? I've seen this symptom before, and...

We need more information...

1) What do you have? (CPU, mobo, RAM, OS, etc)

2) When did it last work, and what did you do that made it not work?

3) When you power it on, at what point does it...

Bad sata controller on the mobo perhaps?

Could be a bad drive. Try:
1) Get a LiveCD of Ubuntu and try to boot off that, see how it does
2) Replace the HDD and try a new install of Windows

Check the docs for your mobo and see exactly what RAM settings it wants. You may have to fiddle with the voltage and speed as caperjack suggested.
Don't forget to let us know if you have any...

When you say "jumped" what exactly are you jumping? If you mean to say you're bypassing some circuit/path/switch in the PSU, you could easily be bypassing a faulty connection or anything else inside...

Your mobo may very well not support that amount of memory - head over to their site and check the docs. Also, are all the ram sticks identical? Some mobos don't like mix'n'match.

Same, I was going to tell you to try loading a LiveCD or GParted or something

Need more info friend. What PC do you have (CPU, mobo, RAM, video card), and what game are you trying to run?

If you're hitting that power button and you hear/see NOTHING, then you're not getting power. Anything else and you'll have SOME kind of life.
It's possible the 2nd PSU you got is faulty. I'd bet...