Dell dimension e520 problems

this computer does not run properly, I have attempted to search on my own as to why this problem is occurring but could not find an answer.
>the computer starts, but does not send a signal to any ports, no monitor, mouse keyboard, nothing. The power light switch just glows amber, and ALL of the diagnostic numbers are amber as well. I am very unsure what to do with this computer, can anybody please be of assistance?

You should start by using 1 RAM chip at a time.
http://support.dell.com/support/ed [...] #wp1054148

I already checked all of the diagnostic numbers from the site there is none that shows all four glowing, but on my desktop all four glow.
I have removed all of the RAM but to no avail, i also removed the one card, but still no juice. i will check to see if it's a harddrive failure, but i really hope that it's not the hard drive, but something much simpler.

http://www.tomshardware.com/forum/ [...] -e520-help

Ok, I don't know i accedentally made this other thread upon signup and the only post in there seems to be the answer.
basically if you go through the link and then click the provided link ( as i do not want to take credit for it, I didn't think this problems occurred this often )
it basically tells you that the cooling supplys in the computer are not sufficient and can lead to the running of either the psu, or the mother board. as with my case all of the diagnostic lights are a steady amber, so i have to think it's the mother board.
so i'm going to take out my hard drive and simply get a new cpu.
which leaves me to ask.



What, If ANY computers, from dell are good, stated to last a long time, and had little problems, that can be either upgraded or comes upgraded.
I was looking at the 9100 series as it comes with a lot of available juice and extra extremities Over my E520, and it looks like it will blend in with my room well.
Can anybody give me a sort of direction on which dell desktop i should purchase.
things to keep in mind ( full time student, will play some games like flight simulator etc, so i will need a decent graphix card, some ram, and i'm covered on the hard drive, as i can simply use my 400 gig from my old computer no?