Problem with Dell motherboard

[cheetoden]

A friend brought me his Dell Dimension 2350 desktop. On bootup there is the error "CPU Fan Not Detected". I assumed the fan was bad and removed it. I plugged it into one of my rigs and it worked. I now assume the cpu fan header is bad on the motherboard and there are no other headers on the board. I can draw power from the 4-pin connectors for the fan but that is not the problem.

On bootup, I still get the cpu fan not detected error. The choices are F1 to contunue or F2 for setup. If I press F1, It goes nowhere and refuses to boot. If I go to setup, there is no way to make the system halt on "no errors" like a "normal" bios.

Is there any way around this?

I can find a motherboard for $30 shipped but wanted to know if the Dell power supply was a standard ATX because I ran into this article while searching for solutions but the article is dated 2001 and didn't know if Dell has become more standard since then.

 

[Steve]

Check the PSU connector pin assignments here: http://support.dell.com/support/edocs/systems/dim2350/techov.htm#1101565

If that's the same as a regular ATX unit you're okay.

 

[cheetoden]

I checked it out with a junk power supply I had here and the color assignments are the same. Thanks!

 

[Steve]

Also check this, just in case: http://support.dell.com/support/edocs/systems/dim2350/replace.htm#1101572

 

[cheetoden]

It would be nice to be able to flash the bios to one that has the abilty to turn off the cpu fan alarm so the computer could continue booting. Do these Dell boards usually have a retail counterpart that one could use the bios from?

 

[o1die]

Ascentech.us has some dell boards for sale. You might one that will fit your case.

 

[cheetoden]

I can't put anything but a Dell board in it because I just noticed the case connections are not normal ATX pins. I'd have to replace the board and the case too.

 

[tcsenter]

Originally posted by: cheetoden
I can't put anything but a Dell board in it because I just noticed the case connections are not normal ATX pins. I'd have to replace the board and the case too.

Case connectors? There are no "ATX" case connectors, there are only ATX power connectors. Intel has the only front panel I/O standard in the industry (Intel FPIO). The front panel I/O pin-outs of the big OEMs are often different from Intel's FPIO standard (as are many motherboards), but they can be made to work by rewiring the connectors or removing the terminals from the connector and plugging them straight onto the corresponding pins (wrapped with a little electrical tape or something).

Re: "CPU Fan Not Detected"

Interestingly, I recently serviced/upgraded an HP Pavilion 514N of the same approximate vintage as this Dell (circa 2002 Intel 845GL motherboard for SK478 Celeron and P4). Instead of using a direct attached cooling fan on the heatsink, it used a plastic duct to direct air over the heatsink from the rear 80mm case fan.

I updated the system BIOS to the latest from HP. After updating the BIOS, the system halted with the exact same error on the next boot. Apparently, HP added a CPU fan sense in the latest BIOS, for a model that had no CPU fan. DUH!

Instead of installing a CPU fan, I just plugged the case fan into the CPU fan header (since the case fan is indirectly acting as the CPU fan, anyway). Problem solved.