XPS Desktops

[Sohail Khan]

XPS 8940 not starting. BIST LED turn on for three seconds and turn off, power supply fan does not start, power button does not do anything. No sign of power at all.

So far, I have tried following.

Removed extra hard drive.

Used different power outlet.

Used different cable.

Any help is highly appreciated.

[RoHe]

If PC is still under warranty, contact Dell Tech Support. Have Service Tag handy.

Running BIST on a PC without a BIST button, like the XPS 8940, doesn't mention anything about the PSU fan, like it does for PCs with that button, so that's an unanswered question about health of your PSU.

If you're using a power strip, surge protector, or UPS, remove those and connect PC directly to a working outlet.

Is the LED on motherboard on 24/7 whenever PC is connected to a working outlet?

Have you checked the power button connector to motherboard? 

It's possible the power button module is the problem, so read this thread.

[Sohail Khan]

Thanks for reply.

My PC is directly connected to the wall power outlet.

There is no light on motherboard.

Power button is connected to the motherboard.

I am going to contact Dell support.

[RoHe]

AFAIK, the XPS 8940 has a small motherboard LED, like other Dell XPS models. So if the LED is off, that suggests a power supply failure.

Post back and let us know what Dell Tech Support says...

[John harper]

This model of PSU only has the green LED no BIST button beside the light.
I currently have the side and front panels removed.
In addition, I removed the RAM modules and the HDD.
The power button does not seem sticky (it makes a sharp clicking sound when pressed).

Regards,
John