HP Pavilion 500 error message of:511-CPU fan not detected

[Big_Dave]

@Thrombus

You should be able to buy a fan controller.  I have even seen low-medium-high switches. Try NewEgg.

[budandpatty]

i have a 500-214 and everytime i turn it on . it comes up with cpu fan not detected and the it says reboot f1

[Jacj1946]

During the HP boot/diagnostics, the CPU fan twitches.  I suspect this is because the fan-checking code is "Start fan", "Check fan", "Stop fan".  Older or dirty fans don't have time to accelerate to whatever speed is required to pass the "Check".  The code should be changed to: "Start fan", "Wait 1 second", "Check fan", "Stop fan".

When the HP code is a few seconds from passing control to Windows, the fan just gets a "Start fan" and runs normally.  I don't know why the HP code stops the fan.  From here it seems pointless.

This problem has been around for a year and cost users a lot of grief.  The solution seems simple to me.

Cleaning fans is a good idea, but only when really necessary.

[Shellyblanco]

Just cleaning the fans fixed the same error during my upgrade.  Thanks guys!

[smilin-dan]

I have this same problem.  Do I need a new fan?  It seems to be working.

[Jacj1946]

I eventually just gave up and replaced the CPU fan.  15 months is not a good lifetime.  I still think the diagnostic code should be changed.

A couple of months later the case fan started to make an increasingly loud noise.  I removed it and cleaned it with WD40.  The fan rotor had moved up the shaft, so  I pressed it gently back into place and ordered a replacement.  The replacement is still on my shelf as the fan has worked fine ever since.

[barryvabeach]

I had the same error message on an Envy 700 -  opened up the case and the case fan was spinning, not the CPU Fan.  I took the connector from the CPU fan and attached it to the leads for the case fan ( only 3 leads v. 4 )  and the CPU fan came on right away - so I spliced the wires in series to the case fan, ( ignored the blue lead )  I still get the error message but the CPU fan is working now. 

[NVY_7]

I have an HP ENVY 700 and started getting this message over a year ago.  We would restart over and over until the computer would boot up fully.  After a while it got to take more and more restarts to get it going.  Finally, I looked to this support forum and found others had the same issue.  I decided to give the dust vacuuming suggestion a try.  It was a good maintenance suggestion anyway and doesn't require much computer experience from a novice tinkerer like me.  However, after cleaning the dust out of my computer and especially giving the heat sink a thorough cleaning, the same issue still persisted.  So, I did what no one seemed to mention in this thread.... I went to Amazon and ordered a new Heat Sink/CPU Fan Assembly for $21.99.  It took me longer to unplug and reconnect the cables than to replace the  CPU Fan Assembly.  Upon reassembly, the computer booted up just fine.  Now I'm kicking myself for not doing this sooner.

Solution:  Spend the little bit of money and get a new Heat Sink/CPU Fan Assembly.

[Cjansen40]

Spoiler

I have the same error message but my cpu fan is not spinning and a replacement doesn’t spin.