CPU Fan speed incorrect

[folivieri]

I have a Dell Inspiron 518 Dual Core Intel E8400 3 GHZ 1333 FSB, 4GB Memory , Vista 32bit system. My question that i have is my CPU fan started making a humming/ buzz type of noise, not real loud just an annoyance ( a little). I did diagnositcs to find out that i had an cpu fan error code 3700:11B incorrect fan speed. with cpu fan showing different rpm speeds like 1878 1875 etc. I dont know what the correct rpm speed is because the dell phoenix award bios doesn't show cpu fan speed or much of anything else, just basic system information. You cant change much either, had been told that Dell doesn't allow you to change much (locked) MOBO etc several yrs ago. My pc system is 3yrs old and i have upgraded the PSU, video card, memory, and CPU from E5200 2.5GHZ to E8400 3 GHZ both dual core. I upgraded the new CPU a few months ago with no problem with the fan until 3/1/12 thats when I began hearing the humming/ buzzing noise coming from the cpu fan. I did some research and replaced the cpu fan / heatsink, but when I did diagnostics again it still shows that error code, new fan rpm speed changed a few times in diagnostics, but I think the fan is fine. The new cpu fan is a Masscooler 2400 rpm one (for LGA775) and doesn't make that noise and is quiet about the same as original one. So if my cpu fan is fine,why does it still say that error code 3700:11B incorrect fan speed. I dont even know the original stock cpu fan rpm speed, thought it might be 1800 rpm, but not sure. the stock fan is a Delta electronics one. Could it be something else?, no problems booting system etc just that error code if i do a system diagnostic. I would appreciate any advice/ recommendations Thanks Frank

 

[JackNaylorPE]

Well on most of my builds the default fan speed has to be changed because otherwise a insufficient fan speed or CPU error is obtained. The BIOS expects a certain speed and it it doesn't see that it wants to protect the CPU.

However, wit big 3rd part coolers, at idle the fan may be as low as 300 rpm. If the default is 600, ya get an error. Change the trigger level to 300 and ya fine.

But if Dell BIOS won't allow ... you have few options. AT 3 yrs old, you are I assume out of warranty. I don't do store bought PC's but one option you might consider is investigating whether it's possible to replace the Dell BIOS with the MoBo manufacturer's standard BIOS.

MAKE SURE you can undo this if it doesn't work before attempting. It's been 20+ years since I have messed with a "store brand" so I am only guessing here.

 

[folivieri]

Well on most of my builds the default fan speed has to be changed because otherwise a insufficient fan speed or CPU error is obtained. The BIOS expects a certain speed and it it doesn't see that it wants to protect the CPU.

However, wit big 3rd part coolers, at idle the fan may be as low as 300 rpm. If the default is 600, ya get an error. Change the trigger level to 300 and ya fine.

But if Dell BIOS won't allow ... you have few options. AT 3 yrs old, you are I assume out of warranty. I don't do store bought PC's but one option you might consider is investigating whether it's possible to replace the Dell BIOS with the MoBo manufacturer's standard BIOS.

MAKE SURE you can undo this if it doesn't work before attempting. It's been 20+ years since I have messed with a "store brand" so I am only guessing here.

Thanks JAckNaylorPE for information, my Dell BIOS and MoBo are both Dell. The MoBo model number is 0k068D socket 775 manufactured by Dell. I did some further research on the fan, the stock cpu fan that i replaced is a Delta Electronic fan model AFB0812SH see article http://www.silentpcreview.com/article689-page5.html. The rated RPM is 4000 which i dont really believe is correct but you never know , my old fan wasn't loud but very quiet like the new one (Masscool model 8WT15-38) at 2400 rpm. My Dell BIOS (Phoenix Award Bios) is the latest version 1.0.8, old version was 1.0.3 version.