Problem with GEForce4 and P4VXAS mobo

[Tengski]

My PC won't POST, gives out 1 long and 2 short beeps, w/ no monitor display (orange light indicator is on - meaning no video signal)

This happens when I put a new Inno3d Tornado GEForce4 MX440 SE w/ 64MB card into the motherboard. When I put my old vidcard back in (a RIVA TNT64 w/32 MB), the PC works fine.

Here's the rest of my PC Spec:
-Mobo: ECS P4VXAS (socket 423) using VIA VT8753 (NB) and VT8233 (SB)
-Latest BIOS Update: p4vxas v1.2b
-RAM: 2x128 PC133 SDRAM
-CPU: P4 1.5 GHz
-PS: 250W

I've read a lot of forums about problems with VIA and GEForce cards, and I've followed all the advices in there already, specifically I:
-ran the latest VIA 4-in-1 update
-ran the latest BIOS update (see above)
-tried tweaking all related BIOS settings using all combinations
-tried disconnecting all hardware not critical to POST
-diagnosed my pc spec using WCPU31a (which reports that I have AGP2.0 enabled, AGP 4X enabled)
-tried putting tape over last two contacts of the vidcard (on both sides)
-tried using the GEForce4 card on another PC (it works fine)

Unfortunately, none of these solved my problem. Any new advice from anyone would be highly appreciated.

Many thanks!

[Telexen]

Have you checked your motherboard manual / manufacturer's website to see what the beeps mean?

[Atomic Rooster]

You may need a larger PSU. 250 watts is a little low. You should try one of at least 300w and higher.

[Tengski]

Yes, it means something is not seated properly in the mobo. However, I've already tried reseating the RAM, CPU, IDE connectors, FDD connector and vidcard a lot of times, and the problem persists.

[Tengski]

Hi Atomic Rooster.

I've already tried disconnecting all harware (hard disk, cdrom drive, FDD, internal modem) not needed in POST activity, to ensure that the vidcard gets as much juice from the PS as possible. However, I still got no POST and no video signal. Wouldn't this eliminate the 250 PS as a suspect?

[Telexen]

Not necessarily. Do you have another system you could try it in?

[Atomic Rooster]

It could be that the mobo doesn't supply enough voltage to the AGP slot that the card requires.

[Tengski]

Texen: Yes, I've tried this GEForce4 vidcard on another PC, and it works fine.

Atomic Rooster: If it's a case of the mobo not supplying enough voltage to the AGP slot, then it would not be solved by replacing the PS with a higher power rating (300W up), right?

[Telexen]

what are the specs on the other system it worked in?

[Tengski]

The specs on the other system:
Mobo: Amax P4X533
RAM: 256MB DDR
CPU: P4 2.4 GHz
PS: 350W