IMac CPU fan speed at full blast.

I have a 20" iMac (A1224) and when you srtat it, the CPU fan goes full blast and never stops.
SMCFanControl reports the CPU fan at 3900 RPMs (full blast) but what is it trying to cool? The temperature is 27 degrees celsius (80° F), Activity Monitor says 93% of my CPU is idle. I've done all the normal SMC/PRAM stuff and it seems that my CPU temps is just fine. Something needs to be replaced.
Sensor
Fan
DC Power Supply/SATA/Inverter cable
Also, yesterday it repeatedly shut down and restarted itself over and over and over until I unplugged it.

I realize that Eric. However, I am currently unable to: https://discussions.apple.com/message/21827955#21827955

Similar Messages

IMac cpu fan running at full rpm

hi all
A few days ago my cpu fan started running flat out. I have done the smc or whatever it is caled reset thing where you unplug the cored ect.
I have done the hardware test with no bad results.
I have checked activity monitor for cpu usage and there is nothing unusual there, so I can only guess that the cpu temp censor is faulty.
I should also add that this machine has been running non stop since mid 2007 , with the exception of the odd blackout and restart, thats pretty amazing i think.
maybe its time has finally come ;(
any clues ??
thanks

SMC is firmware and OS X is software, which has nothing to do. Furthermore, you are using a very old iMac, so SMC should not have been updated with OS X 10.10.2.
If you have tried a SMC reset and it did not work, run Apple Hardware Test (make sure you choose an extended test) to see if there is any problem with a temperature sensor or anything like this -> Using Apple Hardware Test - Apple Support
Note that you may need the DVDs that came with your Mac in order to run it. If you get an error at the end of the test, please copy it here.

IMac CPU fan speed

I recently just had Apple look at my iMac, reason being for the glass to get cleaned on the inside as well as the LCD to get replaced. Waited a week, went and picked it up, only to be disappointed by the fact that the LCD wasn't replaced.
Called Apple, they sent a certified technician to come install my LCD panel. Where he came from, was farther than the closest Apple store near me. Anyway, he came and replaced my LCD, and we tested it to make sure everything was good. It was, and I asked him to leave the glass on, since I was going to be cleaning the insides out. Apparently 3 years of dust accumulation looks pretty gross on the inside .
I ended up taking the motherboard out, to clean the heatsinks and to reapply thermal paste on both the GPU and CPU. They did have an excess amount on, but for the most part was done A LOT better than my early 11 17" 2.3 i7. I ended up taking the hard drive out and swapping it for a 80gb Intel x-25m and tagging the temp sensor on it.
After putting it all together, I noticed that the CPU fan runs around 3700 rpm. I tried resetting the SMC, no luck. I can use fan control or SMC and turn the CPU fan up, but it won't go below the 3700 mark.
One thing to note, is that I have NOT put the glass back on, as I do not have any suction cups. I do know that I plugged everything in correctly, as well as taking the HDD temp sensor from the 1tb stock HD to put on the SSD I installed.
So what could this be?
ps. The Apple certified technician at the Apple store straight up told me that the iMacs DO NOT use thermal grease (I asked him if he could reapply some). HAHAHAHAHA what a dummie.

What kind of thermalpaste did you use? some types of processing units need special kinds of paste.
Are you shure that you have fitted the cooling system on the processing units thight enough?

IMac CPU fan on full speed from start up

Hi,
For about 3 months now I've had a problem with my iMac where the CPU fan runs at full speed from start up, until I turn it off. It is extremley noisy and frustating.
I am pulling my hair out trying to fix it.
So far I have reset the SMC and PRAM and downloaded fan controllers. I've also opened it up and checked the sensors and cleaned out all of the dust, but this annoying problem still persists.
Is there anything else I could try that could fix this problem?
Thank you very much.

Thank you
I have tried to run the AHT many times, but for some reason I can't get it to work. I even tried booting it from the insitallation disk which someone else suggested.
I'm not sure where to go from here

[Solved] Asus L1366 mobo, cpu fan speed control

Hi, everyone,
I finally have this new core i7 system, to replace my old AMD athlonx2. I have one question about the CPU fan speed control.
I remember that in my old system, the cpu fan speed control works out of box, no configuration is needed.
But when I install arch 64 on this new i7 system, the cpu fan is running at its maximum speed constantly while the CPU temperature is modestly low. I know there is a wiki teaching how to do it.
However, I am just curious why it doens't work out of box any more? Does CPU fan control work for you guys out of box normally? especially the new Core i7 cpu users?
Please let me know, really appreciated it.
Thanks a lot.
Update: the issue is solved, see my last post, the solution is blacklisting: asus_atk0110, instead use w83667hg.
Cheers.
Last edited by mark.altern (2009-10-01 08:18:18)

First off, it would be useful to know what the sensors-detect script actually reports.
Okay. How fan control works on Linux: First, navigate to /sys/class/hwmon
Each of these folders, i.e. hwmon0, stands for a sensors monitor / fan controller on your mainboard that may control one or several fans. Inside hwmonN, there should be a subfolder called device, which contains several interfaces if your BIOS allows software-side fan control. You can read them with cat and write to them with echo.
Examples:
pwm1_enable shows if OS-level fan control is enabled (1) or disabled and in BIOS control (0). Changing fan speed won't work if this is disabled. (i.e. cat /sys/class/hwmon0/device/pwm1_enable reports 0 -> disabled; you could enable it with echo 1 > /sys/class/hwmon0/device/pwm1_enable).
pwm1 allows to change fan speed. The values range from 0 (fan off) to 255 (full speed, 12V).
fan1_input shows the current RPM if a fan is connected. You can only read from this interface. Its useful to check all of these in the each of the hwmon folders to find out if there is actually a fan connected to the fan controller (they often have more ports than mainboard manufacturers use).
There might be a fan1_div, this is somehow related to how the kernel reads the RPM, I don't know how it works.
temp1_input interfaces can appeare too, if some of the chips have temperature sensors located somewhere. I *think* lm_sensors places the core temperatures it reads from CPU (the coretemp-isa-000X thingies) in one of the hwmon-folders too.
There might be interfaces for different fans in the same hwmon folder, i.e. pwm2_enable, pwm2, fan2_input, etc., all interfaces with the same index belong to the same physical fan connector, and all in the same hwmonN are managed by the same IC on your mainboard.
Warning: These interfaces, if they work, control the fans directly without any kind of security measure. If you shut some essential fan down, it will stay off until you reboot your CPU shuts down.
(If you see something likein0_alarm, in0_input, in0_max, etc. it's a voltage monitoring chip.)
If one of those interfaces can do something, OS-level fan control does work, if none of those folders contain a working pwm interface, fan control seems to be unavailable.
Sometimes there is an option in the BIOS to enable it, and for some BIOSs software-side fan control only works if dynamic fan control is disabled in the BIOS and fan speed is set to a static value - or vice versa.
I don't know what you are using to control fan speed, there are many applications that use these interfaces, i.e. GNOME or KDE power managers, so I'm not sure what is happening:
IF: Windows 7 enables OS-level fan control and sets it the RPM to those you observed and you have nothing that provides fan control in Arch and so fan control stays at BIOS-level, which might also read out a different sensor / the same sensor differently or it might be more conservative in setting fan speeds altogether;
OR: You have something that provides fan control installed in Arch and it reads out a the wrong value supplied by lm_sensors and thus sets a higher fan speed.
Anyway, possible solutions I can think of:
Find out if you have some kind of fan control software and what it does. For example, I use the fancontrol daemon, I can't help you if you use something else.
The wiki mentions how to assign a fan speed to a certain temperature sensors. You might assign it to a different one. For example, there are no sensor chips on the mainboard of my EEE (no temp1 etc.) so I assigned the fan speed to the temperature reported by the BIOS via ACPI (those are in /sys/class/thermal, also no "device" subfolder on EEEs):
FCTEMPS=/sys/class/hwmon/hwmon0/pwm1=/sys/class/thermal/thermal_zone0/temp
You could also change the MINTEMP/MAXTEMP values to one higher than those you actually want to compensate for the effect of lm_sensors reporting temperatures that are too high.
It is currently not possible for a mortal user to change the coretemps lm_sensors reads, see this post, last paragraph.
There is a configuration file, /etc/sensors3.conf, you can change sensor names and adjust offsets here, but only for the monitoring chips and their sensors that are on the mainboard.
Last edited by Malstrond (2009-08-19 19:34:22)

CPU Fan Speed always LOW? -- K8N NEO4 Platinum SLI

I'm wondering if anyone can help me out. My CPU fan speed is consistently around 850 RPM, both at idle and under full load. This is shown in the BIOS, with Corecenter, Everest, and Speedfan. I have Cool n Quiet disabled in the BIOS, CPU Fan Target in BIOS set to 40 deg (have had it at 60 as well), and Windows Power Scheme set to Minimal Power Management. I've even tried enabling Cool n Quiet to see if it actually did anything...but fan speed is still the same.
It seems everyone else has CPU fan speeds in the thousands rpms. Mine never changes, is always around 850.
My CPU temps vary between 37C idle and 48 load when my ambient room temps are around 75 deg.
What's up with my CPU fan?
EDIT: Speedfan doesn't seem to work for adjusting anything. It only shows my CPU (fan2) and NB (fan3) fan speed, but adjusting the percentages has no effect.
My Config
MSI K8N Neo4 Plat SLI
Athlon64 3200+ 939 Venice
1GB (512MBx2) PC3200 DDR OCZ Value Series 2.5-4-4-7
Leadtek GeForce 6600GT
Hitachi 7K80 SATAII 80GB x 2 in Raid 0 (nVidia RAID controller)
Antec True Power II 550
Maxtor 80GB + WD 80GB 7200 RPM on IDE1
Sony DRU-500A DVD+/-R/RW
Windows XP Pro SP 2

Try setting cpu fan speed to max to access this open corecentre & click on logo.
should give:-
Select user mode & set Fan to max. This info is held in the corecentre chip & is the only way to access it .
Only keep corecentre installed for this function
hope this helps.

Imac high fan speed and goes to sleep 10sec after wake-up

Hi,
Since today my imac's fan speed is high (optical fan and cpu fan speed at: 4000rpm)
Done a hardware test wich gives me 4SNS/1/40000001:IDSR-0.000 indicating something with logic board. According to istat all my temperatures are below 35°C (95°F). istat has readings for the cpu and optical drive temp (both around 26°C)
On top of that if I put my imac to sleep after wakeup (give or take) 10sec later it would go to sleep again. tried the smc reset procedure. no success
Any other tricks to try or just go for an exchange? (imac was bought on 2feb2010)

I've had this problem since replacing the MLB in my iMac a few weeks ago. Initially brought in for repair when the CPU fan came on at 4k rpm and stayed on even after SMC reset and nvram reset. First replacement MLB was a dud, second corrected the fan problems. Now I'm having the sleep issue, I can't tie it to any particular process. Initially I thought it was graphics related as it would go to sleep during graphics intensive work, but yesterday it was doing it when just copying data to an external drive. The temperatures of the CPU and the GPU diode are within spec. I now use a fan controller to keep the CPU fan at 2100rpm and the HD fan at 2100rpm and I don't have the problem. From what I can tell now is that a sensor is incorrectly reporting temperatures intermittently. It may not be the MLB or the graphics card specifically, but the cable connecting the sensor to the board. I ran AHT after the last time it did this and it failed a sensor, but after running ASD on the machine it passed all the hardware. I'm bringing it back into my shop later this month and if i can remember i'll post here with the resolution, not much I can do at home beyond software diagnostics.

CPU Fan Speed: How to Adjust?

Hello,
My 975X has what I believe is an issue with the SATA controller, which prevented reliable SATA (hard drive) operation. I went to the local Fry's and replaced it with an ASUS P5Q-Deluxe. One thing noticed is that ASUS has a software utility (AI Suite) to control CPU fan speed. On my 975X, the CPU fan ran "full out". When I looked I didn't see a utility to reduce fan speed: Fuzzy Logic and Corecell didn't seem to adjust the fan speed, but could monitor it. Was there a utility to the control the CPU fan speed that I overlooked? If so..too bad..I could've had quieter operation. If not, then I presume MSI motherboards now have a utility to adjust the fan speed so that it scales with CPU temperature, and thus reducing noise? I'd like to know as I'm sure I will buy another MSI motherboard at somepoint. Thx.
Scott

Quote
You replaced it? Or do you still have one?
I still have it, but the SATA controller needs to be repaired; new disks, cables, OS installs, and power supply failed to fix the problem so has to be MB. While I can RMA the board, it is about 3 yrs old so MSI wants $35; not sure it is worth it. Comments?
Generally I've been happy with MSI as I've used their boards for 6+ yrs, but I also really like my ASUS boards.

MSI Max 2 BFIR; Problems with CPU Fan speed in PC Alert!

servus...
First of all, I have Bios version 1.3 from the .de support Page.
I don´t know, why .com.tw doesn´t have this version.
But here´s my problem:
PC Alert doesn´t show a CPU-fan speed!
The northbidge fan shows the fan speed roundabout 5000.
In BIOS CPU Fan ~2500
PC ALert versions:
4.005
4.006
Any ideas?
Thanks

Thank You for the reply,
Before the latest update to PCAlert4 it was working properly, I cross checked the reported info. to that of Sandra, MBM, and in the bios.
Also the temps are only swapped between the system temp. and the CPU temp., other than that they are correct.
Thanks,
John

CPU fan speed problem -- similar to one already posted

Core i7 290
6GB SuperTalent DDR3 RAM 1333 (3x2GB)
BFG GeForce GTX 275 OC
2 120mm case fans (front/back)
Thermaltake CL-P0533 CPU cooler
Vista Home Premium 64-bit
MSI x58 Pro MoBo w/BIOS v.8.3
PCP&C Silencer 750 watt Power Supply
500GB Seagate Barracuda HDD
Yeah, I know that all that info probably isn't that necessary.
Problem: I have a Thermaltake cl-p0533 for my core i7 920. My fan runs 6000+ RPM all the time. I've tried using the overclock center, greenpower center, and the BIOS smart fan thing. In BIOS, I tried setting it to 25% idle and 50c target temp range. No dice. I've tried using speedfan and all that I got was the speed knocked down about 300-500rpm for a bit. My CPU idles at about 33c (according to speedfan and OC center). The CPU fan speed is supposed to be able to be controlled. The noise is really annoying. Any help would be most appreciated.

Quote from: cooldudeguy911 on 30-July-09, 13:51:38
Core i7 290
First, I meant 920 (I must be dyslexic or something)
Yes, the CPU fan is connected to the CPU fan power connector (according to the mobo manual). I've set SpeedFan for the same as I had my BIOS settings. I've since changed them to lower temps. I've tried SpeedFan with and without using the SmartFan feature in the BIOS enabled. My Two case fans are super quiet, so I don't use any regulation for them. So my SpeedFan settings look like this:
Speed 1 - minimum value = 25% maximum value = 100% auto variated
Temp 1 - Desired = 42c warning = 50c
Cores 0-7 = same as Temps 1 settings
I've also disabled the other temperatures for monitoring and fan control
As for the number of wires for the cooler fan, there are 4 going to the mobo.
I don't really know much about add-on fan controller parts. If that's the route I end up needing to go, any recommendations?

Z77A-G45- CPU fan speed problem

Hi all, new to this forum and MSI Motherboards.
i have a problem with my CPU fan speed when i plug any fan and water cooler fan into the CPU 4pin they all run at 2000+ rpm, but when i use the fan 1 or fan 2 --4 pin it runs at a slower speed of 1400rpm, am i missing something in bios, i have 2.5 version of bios, would be greatfull for any help....

Should be able to adjust in the section below or with control center.
Quote
Hardware Monitor
Press <Enter> to enter the sub-menu.
CPU Smart Fan Target
Controls CPU fan speed automatically depending on the current temperature and
to keep it with a specific range. If the current CPU temperature reaches the target
value, the smart fan function will be activated.
SYS Fan1/ Fan2 Control
These items allow users to select how percentage of speed for the SYSFAN1.
CPU/ System Temperature, CPU FAN/ SYS FAN 1/ SYS FAN2 Speed
These items show the current status of all of the monitored hardware devices/ components
such as CPU temperature/ system temperature and the few fans’ speeds.

MSI H81M-P33 Cpu Fan Speed Problem! Urgent

Hi. Bought a H81M-P33 board and got a problem.
I can´t increase my CPU fan Speed to maxium RPM . Tried to use Command Center and Board Bios without any sucess.
This leads to my cpu (i5 4670) getting hot with stock cooler. When I´m encoding a video it reaches 85º. The best solution I had was to connect CPU Fan to Chassis Fan slot on the motherboard and it increased speed, but still it doesn´t increase past a certain value.
What can I do to solve this problem? Tried everything without any luck. The board doesn´t handle CPU fan speed + temperatura increase well. Is not normal to have a CPU stock volts getting hot.
Thanks

I know that for sure XFM. The thing is that the board isn´t increasing CPU fan speed as it should. Ofc a better cooler would do the job, but even with stock cooler it can be cooler. The problem is that the fan is always in slow mode :|

Motherboard or CoreCenter controls CPU Fan speed?

I have the 865G Neo2-PLS board running 3.6 bios.
I'm not so sure I want to use CoreCenter; but I liked the way it adjusted the CPU fan speed, based upon the temperature reading. Or was it the MB itself doing the adjusting? I know the CPU has a feature which throttles down activity if it gets too hot, but I'm curious what controls that CPU fan automatically. Thanks.

Hi
I must say that am very happy with Corecenter in automode!
I have it on my autostart in the program list! It kicks in automatic and controls the rpm of the CPU fan ( 1300 - 2200rpm) depending how much I push it!
I have never had any problems with it...........Use liveupdate to get version 1.6.2.0.
I must say that zalman have saved my day......its silent.....hmmmmm silent...

How to reduce cpu fan speed just by hardware?

Hi,
I have a K8N Neo4-F, AMD3200+ and "arctic cooling freezer 64 pro" as cpu fan. The rpm range of this fan is from 300 to 2200. I use "cool n' quiet" and "Smart CPU Fan Target with 40°C" as bios setting. When the cpu is idle ( ... just doing some typing or so on ...) it has a temperature of 32°C and the fan has ~950 RPM.
I think the fan speed is to high for this cpu load (< 5% and 1000Mhz CPU Clock). My expectation in this szenario is to have the cpu fan speed near the lower bound (300 rpm), but I don't know how to manage this (with just bios settings) ... any hints?
Thanks a lot ...

Quote from: Kwea on 12-January-06, 22:29:54
My point was you did what D.O.T. is supposed to do without using it.
Of course it's point is to auto-overclock the system to whichever degree it's set at. The problems come in because a lot of the settings it uses aren't always compatable with a lot hardware combinations. That's why it's best to come up with your own OC settings that are stable with your parts.
It's just like how the Nvidia/ATI speedup option seems like a good idea, but works poorly in practice.
Both are more useful to the marketing dept. in having more "why tech" features available to print on the outside of the retail box than they are to the end user.

CPU fan speed on P45 Neo3FR

I just installed Coolermaster Gemini iis cpu cooler on my system. From the HW monitor, I found that the max fan speed was only 1867 rpm. A similar reading was found on the reading of DualCorecenter utility. I have put the CPU fan speed in the bios to maximum but no change. The support center of coolermaster has confirm that the fan is able to run up to 2000 rpm.
Does anyone have a suggestion?
My system is
mb: P45 Neo3FR pcb 1.0
bios 1.8
CPU : E8200
PSU : Antec pure power 430

I tried the options in the smartfan, but no response. The fan speed did not change. Actually, my problem was the cpu temperature is about 1-2 degrees higher than the stock cooling. So, I took of the fan, cleaned both CPU and cooler, applied the correct amount of thermal paste following your suggestion. Now, the CPU temperature is about 40 to 41 C during idle compare to 43 to 44 using stock cooler. The fan speed has increased to 1910 rpm.
I just wonder that the fan speed may not properly regulated by the bios. Do you think it is necessary to tell MSI support?

IMac CPU fan speed at full blast.

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