Ok, my neigbors Dell Dimension 8400 appears to have a defective PSU. I know that there is a proprietary situation with Dell Computers and their PSU's. Tried to log in at Dell to find out, but they always ask for a Service Tag number for any kind of help and my neighbor doesn't know what it is. So, does anyone know if there was a point in time when Dell started to use off the shelf PSU's for their computers or is this proprietary situation still stand true at Dell? Any comments would be appreciated. Thanks.

Someone once suggested comparing the wire colors on the motherboard connector with a generic power supply.

Do yourself a favor BACKUP!

It may have been me that suggested that?

http://www.bluemax.net/techtips/ATXPowerSupplyWiring/ATXPowerSupplyWiring.htm

I have an 8400. I entered my Service tag # and got: *For prices and availability on spare parts for this system call 1-800-357-3355.

However, it is a 350W PSU and the connector is on the top left with the fan to the right of it.
It is behind the case whereas you have to insert the power cord though the hole in the case and into the PSU.

On an older Dell I tried putting in a generic PSU but the cord connector was not in the correct position unless I wanted to cut through the case.

I believe it was this fact that made it proprietary.

Otherwise a 350w PSU is a 350w PSU. All the connectors are the same.

Bryan

Dell proprietary systems was made between 1996 and 2000. The wire colors will tell you it is wrong. If the colors are as per link in post by JAM then it is a standard supply.

Info came from "Upgrading and repairing PC's by Scott Mueller"

The Service Tag can also be seen in the BIOS screen (F2 at boot).

Ok, thanks. I'll my neighbor follow up on all the information given here to get his machine back online.

on the dell i am using right now the service tag is on a sticker under the flap that covers the front usb sockets.
Even 'standard' ATX PSUs sometimes use different coloured wires, even though they are interchangable.
So if the wires are different colours it is not conclusive that the PSUs are not interchangable, but I would be very wary.
Sometimes PSUs have a label on telling you what each clour wire is for like +12 volt, +5 volt etc. this might help match it