Recently built pc new.

AMDxp3200+ 400fsb
Heatsink- aerocool, using arctic silver thermal paste
3200 1gig dual channel cosair ram
gigabyte ga7n400pro2 mb
400w power
radeon 9600 256mb 8xagp graphics card
western digital hd 200gig
dvd rom and other bits and pieces.


Was fine then upgraded heatsink. When i turned it on no signal from monitor.
All parts are compatible, with enough power.
The mb light shows the dimms are in dual channel, the heatsink, and all fans work, the hard drive light is active, the reset seems to work, and the agp non comatible light is off. The only problem that i can see is that there is not signal from the monitor.
there is also a strange short buzz (not bios beep)sound at statup even with just processor and heatsink on mb-dont remember this b4 but otherwise normal sounding boot.
Tested the monitor/cable on another pc:works fine
Bought an old pci graphics card to test in case agp slot or graphics card was broken, -still didnt work (i think it is a compatible one-bought off ebay tho for £5)
Thought it had to be mb or cpu so Sent both back to shop-they were apparently tested faulty and replaced though they may not have been checked properly.

Got back today and installed parts:
system still the same-seems to boot normal (except buzz) but no signal form monitor! (which is plugged in by the way)

The only thing that i can think of that i may have done wrong was get a bit of the arctic silver on one of the the diody things around the slug on the processor. i have heard from pple that it can be conductive and bridge two and short it.Is this possible because i think i did this both times(just a tiny but tho).
Can i use methalated spirit to get it off? i dont wana scratch the slug-Theyre not guna wana replace it again.

i'm guna have to try2 send the graphics card back next as i have no other system to test on (that any1 will let me take apart)
i'm guna get charged if its not tested broken and the onboard heatsink on it does get warm so there must be power going in!
I placed the card ontop of the tower unit once- could that have charged it and damaged the ic chip?
i cant tell if the processor is heating up coz its got a giant incased heatsink ontop but the boot sounds are normal (except the short buzz)
i cant think of anything else to try except install the old heatsink back on.
ive tried running with just graphics card, cpu, mb, ram installed and its the same.
The buzz occurs even with just the cpu, mb and heatsink so it must be coming from one of them(or the case or powersupply)

I dont know what i've done that has made it not work!
Been without a computer for 2months now.
I heard of lots of pple having similar problems
Pllease help me anyone

are you still having problems