Need help quick! Dell computer not turning on

[cryptic5.0]

Ok, just bought a used Dell Precision 340 to use in the shop, and when I turn it on, it makes a beeping sound, and the "a" and "b" lights on the back are amber, while the "c" and "d" are green. It won't do anything.

What is causing this? I know the computer was working a few weeks ago. All the guy did was unplug it and set it in the closet.

Please help. thanks.

[Blue5spd]

It sounds like a hardware piece has gone out on the machine. Probably the motherboard or power supply.. Can you access the bios?