I recently bought a new computer (all the parts and assembled them myself)

I have a

abit nf7-s motherboard
amd athlon xp 2500+
512 pc3200 ram
maxtor 40gb hd

when i turn the computer on the fans and lights work, but nothing shows up on the monitor, it acts as iff the computer is still off. the BIOS does not come on

so far i have tried to use a different hd (and used hd on another computer) and it is not the HD, I have tried the same for the video card and monitor

then i thought the ram was installed incorrectly (which it wasnt) and put it in the wrong way after i did that turned my computer on, it shut off after about 2 seconds and i noticed a burning smell i quickly took the ram off and installed it back the right way

I tried the ram on another system, works fine

does anyone know waht the problem could be? the bios was not working even before i screwed up

You should buy a complete PC and not assemble things yourself - or at least get a knowledgeable friend to help you - when you are not completely sure how to do it. There are several things that could've been wrong, like something that wasn't inserted fully/properly (RAM, CPU, even graphics card) or maybe something trivial, like forgetting to put heatpaste on the CPU. However, putting in your RAM the wrong way might have fried your motherboard.

Do me a favor, read this page thoroughly from top to bottom (check this if it doesn't load) and tell me if there is anything (maybe except point 2.2 and 2.8) that you left out or did in a different way.

I have done everything but in section 2.10 i do not have a Speaker Connector plug.

also before the RAM incident I didn't hear any beeps from the computer when I turned it on

I don't know if your motherboard is still useable after the RAM-burning smell incident, but sometimes and especially with AMD CPUs, the power supply is not adequate. What kind of power supply have you installed on that machine? Does it satisfy AMD standards?

i am using a 350W power supply that came with the case

the case i am using is a x-dreamer ii case