Turning Computer On And Beeping

I've been having really bad computer troubles recently and really need some help, cause I've wracked my brain trying to think of possible solutions here.To give a bit of background:The computer in question is an AMD Athlon 1800+ that I've had for about 3 years now. It's not the most stellar computer, but I mainly use it to surf the web and play some low-end games nothing spectacular.Recently however it had started to reboot constantly, and eventually just power off and never come back on. I figured it was the power supply, so I purchased a new 400W one, installed it and everything was working great.Fast-forward a couple weeks later, and I started to hear a really odd noise coming from the computer. It sounded almost as if sparks were flying around inside, but I removed the case and checked what the problem was, and it seemed the CPU cooling fan was having some troubles, and eventually stopped working. So just today I went out and bought a new CPU cooling fan, installed it, and again, everything was working fine.

However, just tonight, the computer began to reboot randomly again, and now it is at the point where it will not turn on, and when I do power it on, it just idles and beeps constantly. They are fairly short beeps, but they continue on and on indefinitely. I read up on the beep codes and how they coordinate with the BIOS setting, but problem is I have no idea which BIOS setting I have, so I am not sure what could be the problem. To be safe, I began to unplug the cards one by one, seeing if any of them stopped the beeping, but to no avail.So I am at a total loss here Having just bought those two things recently and STILL having the computer act like a pile of garbage is disheartening to say the least, and I just hope someone may have an idea on what or how I could fix this.