# Dell PowerEdge 700 - Back Fan Not Detected Error



## larryo108 (Aug 9, 2010)

All:

I am hoping that someone can help me with this issue I am having. I recently bought a used Dell PowerEdge 700 server to build into a home server for myself. I want to set the computer up with an internet connection and a network connection. I plan to remote desktop in for monitor, keyboard, and mouse. This will allow me to not have to have a separate monitor, keyboard, or mouse or a KVM switch. 

I am having a frustrating issue though. Everytime I boot up I get a "Back Fan Not Detected" error and have to press F1. Since I plan not to have a keyboard, this will not work out very well for me. As you can imagine.

The previous owner replaced the stock Dell fan with an aftermarket Enermax fan. It is a 4-pin fan and when I originally bought the tower, it was simply wired directly to the power supply with a hot and a ground. The other two wires were essentially left disconnected. It worked, but I got the above error.

I am pulling my hair out looking on the interweb for a solution where I can either turn off the alert, or somehow bypass the sensor. I have been through the BIOS a hundred times and there is nothing related to the fans that I can see.

I found a solution to jumper pin 1 to 3 that seemed to work for others, but when I tried it and hit the power button the computer would do nothing. I would remove the jumper, discharge the power button and try again. Everything booted fine with the exception of the above error.

Finally, I bought a conversion cable to go from the Dell motherboard fan header to a standard 3-pin Molwex connection. The computer boots and the fan works, but I still get the damn error. I had read that you could use the 4-pin fan with a 3-pin connection, you would just lose the RPM or voltage monitoring that the fourth wire provides.

Any help with this issue would be most appreciated as I am just trying to get this server up and running for myself. Thanks.


----------



## Tyree (May 10, 2009)

Every Dell that I have had in my shop needed to have the original dell wiring configuration attached to prevent the notification.


----------



## larryo108 (Aug 9, 2010)

Are you saying that I have to have a Dell Fan? The replacement would cost more than the tower I bought used. I have read on other Dell towers with a similar issue, that you can bypass the sensor with a jumper, a conversion wire, and/or a BIOS setting. None of which have worked for me. Thanks.


----------



## JimE (Apr 16, 2009)

You will need to find the correct fan header/connector that the back panel fan should be using. The BIOS is looking for a signal on a certain header. Then, assuming that header is still functional, simply buy a 3 pin or 4 pin fan and cable. Connect it up and it should all be good.


----------

