System will not boot after adding ram

[exhibo]

Something happened after upgrading just an extra 512mb of RAM to 3.5gigs... my machine just will not boot up. I have tried removing all the ram, the power cable and held the power on button for a minute, or so, but still nothing. I've gone back down to 2gigs and still nothing. Each time I leave it for 5 mins and try it, I can hear a tiny spark of power, but nothing follows..
[updated] I just unplugged each set of connector cables from power supply and found the pc powers up fans on full when I disconnected a block of 4 (2 yellow,2 black) going to the motherboard.. any tips to help direct me from here? thanks in advance.

 

[crjdriver]

I put this in your own thread. When you have a problem, post your own thread. The reason for this is that with one issue per thread, it is difficult at best to follow what has/has not been done; with two or more issues, it is impossible.

Now as to your problem. What you are unplugging is the additional cpu power connector. I would try a new power supply however I tend to think you have a failing motherboard. A new power supply is the easiest way to troubleshoot the problem.

If you do not have a known good unit to swap in, go to compusa and pickup a new antec unit. If it works, great. If it does not work, they will let you return the pw supply.

 

[exhibo]

Ok..sorry for posting on another thread. Thanks for the advice - I'll try out a new power unit, but fear it is the motherboard too.