CRYSTALIDEA Forums

So I have a 09 imac that has no screen. I got it that way so I use an external monitor. Because of this and the fact that the hard drive was replaced I have the stupid crazy fan issue.

After trying out the best fan control programs I chose Macs Fan Control but in the process the Min Fan speed for the ODD fan got messed up and is now stuck at 5100 (which is the MAX speed as well).

I have tried everything - from resetting SMC to deleting every possible fan control file on the hard drive to putting in a whole new hard drive that had no fan control remnants on it but nothing has worked.

It does go under 5100 but the only way is to first open Macs Fan Control and then SMC fan control, quit Macs Fan Control, and then open it back up. The ODD Min RPM speed will then go to a random number like 2264 like it is currently. The odd thing is that if look at the preferences of SMC it shows the ODD Min RPM speed at 1500. It used to show 5100 but I manually edited the plist and then it went down.

I don't understand what is controlling the Min RPM. Does anyone have any idea what I can try next?

MarkimusPrime
The current version is not able to edit min speed. Do you have a technical information or screenshot of MFC on you iMac?

The situation looks like you have a problem with SMC firmware

Yeah here's a screen shot. That is what it is at currently (2264) - after I had quit Macs Fan Control after startup and reopened it.

Upon start-up though it'llI have 5100 across the board for ODD.

I am pretty convinced it is an SMC Firmware problem too. Especially because two separate hard drives both had 5100 min rpm. Hopefully the next update may be able to fix this problem. If not, do you know what can be done other than resetting the SMC...is the SMC something that is an interchangeable part in the computer? Or a new ODD fan/cable?

Ultimately I can deal with it as long as I get lucky and the Min RPM is randomly set in the 2000's somewhere after reopening upon start-up.

MarkimusPrime
min RPM for ODD fan is 1600 on your mac.

I do really think now that the problem is that you're using smcFanControl together with MFC:
http://www.crystalidea.com/macs-fan-control-faq
Section: Conflicts with other fan controlling software

Thanks for your help so far.

I deleted all fan control from the device. All the plists and everything. Restarted it. Then downloaded only MFC and it was still at 5100. So it wasn't being used with anything else.

Restarted it

Shutdown, not restart

Okay. I will do it again and make sure to shut down. I'll let ya know the result.

Okay so I tried it all again and no dice. I only downloaded Macs Fan Control and still it was stuck at 5100. But then I exited MFC and reopened it and it went down in the 2000's. Repeated that process and then it randomly showed a different Min RPM.

My SMC is just messed up at this point. But because MFC is able to show a different Min RPM than 5100 after restarting it I'm thinking that the next update where you can change your minimum RPM (decrease in my case!) would be helpful if it worked to truly decrease.

Here is the technical information. That Darn ODD min is always changing lol I did however lock in the RPM at 2074 so every time on startup now the Min is 5100 but it will be constant at 2074. Not perfect but it will work.

Macs Fan Control 1.1.11, iMac9,1, Mac OS X 10.9

Fans:
ODD-min{2074}curr{2139}max{5100}mode{2,TO0P,20,25}
HDD-min{1600}curr{1599}max{6000}mode{2,WDC WD1600JS-40TGB0,42,52}
CPU-min{1200}curr{1867}max{3900}mode{2,TC0D,20,28}


TempSensors:
TA0P (Ambient) - 19
TC0D (CPU Diode) - 22
TC0H (CPU Heatsink) - 22
TC0P (CPU Proximity) - 25
TG0D (GPU Diode) - -1
TG0H (GPU Heatsink) - -1
TH0P () - 26.125
TL0P (LCD proximity) - -1
TN0D (Northbridge Chip) - 50.1992
TN0H (Northbridge) - 47.625
TN0P (Northbridge Point 1) - 33
TO0P (Optical Drive) - 20.125
Tm0P (Mem Controller) - 24
Tp0P () - 23.2344

The only left that I can think of is that sensor is bad? I swapped one out for a 2007 imac but it either didn't recognize it or confirmed that it isn't the problem.

Does anyone know if these things are interchangeable? Mine calls for part 593-0866 and I used a 593-0493 to test it. Both are 2 pin connectors so I didn't know if they are interchangeable.

MarkimusPrime
I don't know as I don't have this mac

You could try finding the 593-0866 cable somewhere from the same mac...

On ebay there are not really cheap
http://www.ebay.co.uk/itm/Apple-922-882 ... 0636667008
http://www.ebay.com/itm/593-0866-Apple- ... 1e8d83e011

MarkimusPrime
I have an idea, try running Apple Service Diagnostics (Intel), you need 3S132 for 20 inch 2009 iMac (google for it)

Yeah I found one for $12 on a website so I may try that.

I will try that and get back to you with results.

Once again thanks for all your help so far.

Also do you know if holding a fan's rpm at a constant value will cause the northbridge chip and almost everything to increase in temperature? If you look at this screen shot compared to the one above everything is hotter and my computer is doing nothing different.

You have to play with settings yourself.

Generally ODD is not responsible for cooling CPU/Northbridge