Quadro FX (AGP) boot problems

First I want to tell you this card is working, works every time in another pc with an athlon 64 motherboard (can't remember model but it is DFI)
Secondly I am not 100% sure on what the model of the Quadro FX is (I lifted the heatsink to apply arctic silver and the core says GeForce 6800LE so I assume it is a FX4000)

Now to the problems, this card almost allways refuses to boot in the system I want to put it in (Athlon XP 3000+, Asus A7N8X-E Duluxe, 2GB samsung ram, 160gb Hitatchi SATA HDD)
Whilst it sometimes boots (though windows is yet to be installed) most of the time there is no display and the card itself emits a never ending beep from the buzzer built onto the card, and the fan dosn't spin, there are no error beeps from the motherboard (The motherboard works perfectly with a BFG 6600gt and an ATI 9800 pro, and X800 so I know everything else is working ok).

Any help with this problem would be appreciated as I was hoping to be able to re use the Althlon XP as I don't need the machine to have a powerfull cpu.

umm, it could be that the power supply isnt powerfull enough.

other than that, it could be a faulty slot on teh mobo

power supply is 550W Jeantech, and I have tested a GeForce 6800GT on it, so the power supply and AGP slot work fine.

the fan not spinning isn't a good sign. I found something on some dutch website through google that said:

It has an integrated buzzer that'll warn you if the card is overheating, ... Within the SPEC Viewperf results we saw the Quadro FX 3500 match the Quadro ...
www.techzine.nl/rss/exreviews.xml

So perhaps since the fan doesn't appear to want to spin, the card rapidly starts to overheat and the buzzer kicks in to tell you so. Are you sure that the fan is connected correctly (can you see the power cables)?

One way of getting the fan to spin might be to hook it up directly to your PSU, however i wouldn't wholly recommend that and it'll probably just run flat-out forevermore. However, if it gets it to spin and the system to boot, you might have some dodgy connection on the board?

When it boots up, the cards fan spins, and when it fails to boot it dosn't, so I have the feeling that there is a problem with the fan, and the card is able to tell it isn't spinning and is thus refusing to boot.
I have another hsf that should work ok on it(though it will be a temp solution to test it, if it works I will get an arctic silencer), so I will try hooking that up to it, hopefully that will be the problem (I doubt there is any heat damage as the times it refuses to boot I turn off the pc quickly and the heatsink never seems warm after)

EDIT: Would I be wise to leave the ram heatpipe\heatsink arrangement attached to the card, or would it be safe not to use it?

Update:
I attempted to fit the cooler I have onto the card, but was thwarted by nVidias insistance on using non standard mounting holes, so instead I put my thinking cap on, and simply mounted the fan from that cooler onto the heatsink of the default cooler, this gave me a better opertunity to see what happens at boot (I tested the standard fan and it works fine when not on the quadro) what seems to be happening is that the card will spin the fan up (albeit slower than maximum) then it seems to stop and the buzzer wails at me (I could see the movement of the new fan much better due to it having a led built in).

I am certain that my power supply is powerfull enough (the other pc I tested it on has 2 more hard drives, 3 optical drives and the exact same model of power supply and it somehow seems to work ok in that)
Could it be motherboard incompatibility? are there any issues with the nForce 2 ultra chipset and quadro cards? or is asus's agp port out of spec somehow?

I am well and truely stumped.

No one have any ideas?