Inspiron 1520 laptop cpu fan not working

Thank you very much for the reply. It would appear to be a software issue. I went into the diagnostics and while the tests were running, I noticed the fan had come on. I ended the tests and rebooted normally, and the fan stayed on until a few minutes after windows finished loading, then it turn off, and has stayed off even when I load the processor.

P.S. Now it seems to be working fine. Fan is turning on and off as I use my computer normally.

I have been looking through the Dell Forums for an answer to this very question!  My brother's Dell Inspiron has developed this same problem.  The computer techie who worked on it found the CPU fan was not working.  Actually, his quote, the CPU fan comes on and then goes off.  However, he didn't say anything about it coming back on.  The symptoms are:  Computer boots, runs for just a few minutes and shuts down.  The techie opened it and found that on bootup, the fan starts, runs for a short period of time and shuts down.  It doesn't start after that.

My brother bought an under computer dual-fan gizmo and the computer has run 6 straight hours so far without shutting down.

All that to ask this:  What diagnostics did you run and how do you know that the fan is cycling on and off as needed?? 

All I did was hit F12 as the computer was booting up and chose Diagnostics from the menu. Once the Diagnostics start, it automatically starts running certain tests. During one of the tests, it puts colored bars across the screen and asks you if they are displayed. After I told it yes is when the fan came on. I then canceled the tests and let it reboot into Windows normally, and the fan stayed on the whole time until a few minutes after Windows finished completely loading. I then run SpeedFan and RealTemp, which are programs that monitor the computer's temperature sensors. I installed them a few days ago when I started having issues with my computer locking up from overheating. I then starting using other programs so that I can see their effect on my sensor readings and when my fan would turn on and off. I would either periodically flip my laptop over to see if the fan was moving or not, or hold my hand under the laptop and feel whether or not air was moving past my fingers. The fan continued to turn on and off all evening, but the temperature readings I was getting were a little higher than I would have preferred. Today I added a larger fan sitting external to the case right underneath my proc, and it is keeping my computer a lot cooler. Without the fan, SpeedFan would report that my cpu temp would get as high as 60 degrees Celsius, but with the fan, I can't get it to go over 45. Right now, SpeedFan is reporting 28 degrees, while RealTemp is saying 43. I don't know which program is more reliable, or why they are reporting differently, but these numbers are more than fine with me.

Hi,

I have the same issue and have a couple of questions:

to access and replace the fan did you need to take all screws underneath? were you able to test the fan before putting the laptop back together?  does the whole bottom cover comes off? sorry, I've never taken my laptop apart and would like to know this before I do the job.

Thanks...

He most likely Hit F12 (boot selection), at startup, and selected the "Diagnostics" option at the bottom of the Boot list.  Runs automatically and prompts you to respond when necessary.

"It is better to remain silent and be thought a fool than to speak out and remove all doubt"  -Abe Lincoln