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IDProjectCategoryView StatusLast Update
0001802SpeedFanFan controlpublic2019-02-12 08:01
Reporterhugheaves Assigned Toalfredo  
Status assignedResolutionopen 
Product Version4.43 
Summary0001802: Issue controlling fan speed on FINTEK F71858
DescriptionI'm attempting to use SpeedFan to control the fan speed on my Dell Zino HD (Inspiron 400) mini-desktop system.

SpeedFan detects four PWM ports on the SB7xx/8xx PM2 and three ports on the FINTEK F71858. Only the first two fan speed inputs (Fan1 and Fan2) on the F71858 are connected. (One is for a CPU / case combined fan, and the other fan is for the GPU). Fan speeds, CPU and board temperatures, etc. all appear to be detected without issue.

The problem I am having is trying to control the speed of Fan1 and Fan2. By default, the F71858 outputs are set to "Auto Set PWM" which doesn't allow me to make any changes to the fan speed.

When I set the PWM1 output to "Manual Set PWM", I can set the fan speed of Fan1 to about 1900RPM by setting the speed value to 1% or greater, or I can set the fan speed to around 5600RPM by setting the the speed to 0%. If I set PWM1 to "Manual Set RPM", the speed stays fixed at around 5600RPM, regardless of the current speed setting.

For Fan2, when I set PWM2 to "Manual Set PWM", I can set the fan to maximum speed (5500RPM) by setting the speed value to 0%. When I set the speed value to 1% or higher, the fan turns off completely. If I set PWM to "Manual Set RPM", it turns at maximum speed.

Basically, both fans seem to have reversed logic, and there is no variability between max and minimum RPM. Any suggestions on how to get better control with these PWM outputs?


Additional InformationWin9x:NO 64Bit:YES GiveIO:NO SpeedFan:YES
I/O properly initialized
Linked ISA BUS at $0290
Linked ATI SBx00 SMBUS at $0B00
Linked ISA BUS at $0CCB
SB7xx/8xx PM2 found on ISA at $CCB
Scanning ISA BUS at $0290...
SuperIO Chip=FINTEK F71858
Linked ISA BUS at $0A00
Scanning AtiIgp SMBus at $0B00...
Scanning ISA BUS at $0CCB...
Scanning ISA BUS at $0A00...
End of detection
TagsNo tags attached.
Motherboard ModelDell 0MFHTR
Video Card Model



2011-05-05 18:20

reporter   ~0006174

Uh, first you can try to set REVERSE PWM LOGIC to True..

Then maybe your fan controler is designed to only allow 2 values FullBlast and Min...


2011-05-05 18:34

reporter   ~0006175

Yeah, I did try reverse pwm. It just does the same thing in reverse, although I guess it makes a little more sense that 0% is off, and 1% is full blast than the other way around. :)

I was just curious if this was some sort of F71858 initialization issue, as that device was just added not too long ago.


2017-03-12 04:24

reporter   ~0008471

Last edited: 2017-03-12 05:23


1. I think this chip is not recognized properly. Nothing is shown in configure voltage. It works in all other programs (like OpenHardwareMonitor, Hmonitor, HWmonitor.)

2. Manual control has only 2 speeds:

if Configure | Advanced | PWM 1 mode = manual (with reverse logic)

 100% = 5660 RPM
0-95% = 970 RPM

3. The F71858 chip has an "automatic" mode but its not very good:

 * if Configure | Advanced | PWM 1 mode = 'Auto set RPM'
 Fan speed = 900-1300 RPM

 * if Configure | Advanced | PWM 1 mode = 'Auto set PWM'
 Fan speed = 2470 RPM (OEM/BIOS default)

4. If Configure | Advanced | PWM 1 mode = 'Auto' then manual controls do not work even when "automatic fan speed" is disabled in Speedfan main menu.

= see also:

Manufacturer Specifications

affects: Dell, HP

Issue History

Date Modified Username Field Change
2011-05-04 21:06 hugheaves New Issue
2011-05-04 21:06 hugheaves Status new => assigned
2011-05-04 21:06 hugheaves Assigned To => alfredo
2011-05-05 18:20 DeltaFX Note Added: 0006174
2011-05-05 18:34 hugheaves Note Added: 0006175
2017-03-12 04:24 kf478 Note Added: 0008471
2017-03-12 04:25 kf478 Note Edited: 0008471
2017-03-12 04:28 kf478 Note Edited: 0008471
2017-03-12 05:23 kf478 Note Edited: 0008471