Mobo or PS Problem?

[artistwg]

I just built a PC with a strange problem.

ABIT-IC7-G Mobo
P4 2.8 GHz
512K TwinX SDRAM
Antec Sonata Case with Antec Truepower 380W PS
DVD-ROM
Seagate 160 GByte 7200RPM Drive (Parallel ATA)
Asus Geforce 3 AGP

The Northbridge fan does not run, and the video card and drives show no life.

The CPU fan runs, but all the other fan headers on the board, which are near the PCI slots, do not have power.

When I remove the ide cables, the drives spin.

The Power Supply cables all have proper voltage when I unplug and measure them. The 20 pin PS cable was measured by shorting pin 14 to common to activate the ATX supply.

Possibility 1 - the mobo is not powering the PCI slots and IDE controllers, and the fan headers in the lower half of the board, and is also improperly driving the IDE cables so the drives don't spin until the IDE cables are removed.

Possibility 2 - the 4 pin 12 volt cable for the P4 is powering the CPU fan area of the board, but the 20 pin power is not good under load.

All componants are factory fresh except the Video card (Asus Geforce 3 AGP)

[Alaron]

Try this first: http://forum.pcmech.com/showthread.php?t=12753