Fan Issue 24" (iMac 9,1)

[b06tmm]

I opened up my friend's iMac to clean it out and backup the hard drive. https://forums.macrumors.com/threads/nvidia-heatsink-pins.2095340/.

Now I have the CPU fan running all of the time.

I did the SMC and PRAM reset and installed Macs Fan Control and I can't seem to find anything wrong. I triple checked all of the temp sensors on the logic board and LCD panel and am stumped.

Here is the readout for Macs Fan Control.

If I try to set the CPU fan via the Custom button, I get this.

Here is the diagnostic information from Macs Fan Control:

Macs Fan Control 1.4.8.1
iMac9,1
CPU: Intel(R) Core(TM)2 Duo CPU E8435 @ 3.06GHz [100]
GPU: NVIDIA GeForce GT 130
macOS 10.7.5

Fans:
ODD-min{800}curr{0}max{4800}mode{0}
HDD-min{1100}curr{0}max{6000}mode{0}
CPU-min{3600}curr{3393}max{3600}mode{0}


TempSensors:
TA0P (Ambient) - 19.625, 19.625
TC0D (CPU Diode) - 27, 27
TC0H (CPU Heatsink) - 24.5, 24.5
TC0P (CPU Proximity) - 33, 33
TG0D (GPU Diode) - 26.5, 26.5
TG0H (GPU Heatsink) - 29.25, 29.25
TH0P (HDD Proximity) - 41.5, 41.5
TL0P (LCD proximity) - 26.9141, 26.9141
TN0D (Northbridge Diode) - 83.8242, 83.8242
TN0H () - -1, 128
TN0P (MCP Proximity) - 47.25, 47.25
TO0P (Optical Drive) - 33.75, 33.75
Tm0P (MLB Proximity) - 30, 30
Tp0P (Power Supply Proximity) - 39.1797, 39.1797


Disk drives:
WDC WD1001FALS-40K1B0 - 41

Any help with this would be appreciated.

 

[DeltaMac]

The fans are certainly not reporting properly.
The optical drive, and hard drive fans report no speed (0 rpm), but both of those should be rotating at all times when power is on.
Can you check if all 3 fans are actually turning?

If you have access to an Apple hardware test, you should try running that. It will be on the restore DVD that originally shipped with your iMac when new. If you don't have that DVD, then you can download the AHT disk image, and make your own boot disk, or there's also some steps for making a bootable USB from the image.
https://github.com/upekkha/AppleHardwareTest
There are 3 different images there for iMac9,1 - not sure which one you will need, but it MIGHT work with any of those 3, you would need to test that. If the list is in any kind of sequence, then yours might be the 2nd or third in that list (again, I don't know for sure)
The hardware test should report an error code, which may help you decide where to look more closely.

 

[nambuccaheadsau]

Go back in and make sure the heat sensors are still attached to the hard drive. If the drive was replaced at some time,consider a heat sensor kit from OWC (macsales.com).

https://eshop.macsales.com/item/OWC/DIDIMACHDD09/

 

[b06tmm]

The fans are certainly not reporting properly.
The optical drive, and hard drive fans report no speed (0 rpm), but both of those should be rotating at all times when power is on.
Can you check if all 3 fans are actually turning?

If you have access to an Apple hardware test, you should try running that. It will be on the restore DVD that originally shipped with your iMac when new. If you don't have that DVD, then you can download the AHT disk image, and make your own boot disk, or there's also some steps for making a bootable USB from the image.
https://github.com/upekkha/AppleHardwareTest
There are 3 different images there for iMac9,1 - not sure which one you will need, but it MIGHT work with any of those 3, you would need to test that. If the list is in any kind of sequence, then yours might be the 2nd or third in that list (again, I don't know for sure)
The hardware test should report an error code, which may help you decide where to look more closely.

Thanks for your suggestions.

So far I have had no luck running the AHT. I've tried all three 9,1 the latest 8,1 and the first 10,1. I can boot up to AHT but once selected the computer boots normally into a user. I checked to see if I needed a firmware update, I do not. I called my friend to see if she has the install disks, which she should as I gave her the computer.

I'm now going to try and burn the original USB image and see what happens and then lift the LCD a little to see if I can determine if the other fans are running.

Edited to say that I believe the USB restore stick was from my old Macbook Air, not the iMac. I'll just wait for my friend to call back about the utilities disk.
[doublepost=1513528597][/doublepost]

Go back in and make sure the heat sensors are still attached to the hard drive. If the drive was replaced at some time,consider a heat sensor kit from OWC (macsales.com).

https://eshop.macsales.com/item/OWC/DIDIMACHDD09/

I triple checked the sensors. I did pull the HD to copy her data off of it but I was gentle with it

 

[b06tmm]

Can you check if all 3 fans are actually turning?

I pulled the LCD off and the HDD fan is not spinning and the ODD fan spins for about a second and then stops for five seconds, then spins for about a second and so on.

It looks like I can order these fans for $2.50 each so I may do that.

 

[DeltaMac]

You can spend your money any way you like.
One fan could fail, although not likely. Two fans fail at the same time? Possible, but way down the list in probability.
(I think you have a connector that needs to be properly connected. It may be on the back of the logic board. That's more involve

I still believe you should try the hardware test.
What happens if you simply boot while holding the D key? (If the hard drive is original, and has never been reformatted for a clean install, the hardware test should still exist in hidden partition on the drive. If restart while holding the D does not work, either, then, you might be able to download the apple service diagnostics for this. You can search for ASD 3S132, (correct for testing your iMac9,1) or even look here. There's good instructions for how to use ASD at that link.

 

[b06tmm]

You can spend your money any way you like.
One fan could fail, although not likely. Two fans fail at the same time? Possible, but way down the list in probability.
(I think you have a connector that needs to be properly connected. It may be on the back of the logic board. That's more involved.

I agree with the two fans failing proposition, but the HDD fan which is not moving was clogged almost solid with dust. Also, all of the connectors for the logic board are on top of the board, and if you look at the first picture I posted all of the temperatures are reporting.

I still believe you should try the hardware test.
What happens if you simply boot while holding the D key? (If the hard drive is original, and has never been reformatted for a clean install, the hardware test should still exist in hidden partition on the drive. If restart while holding the D does not work, either, then, you might be able to download the apple service diagnostics for this. You can search for ASD 3S132, (correct for testing your iMac9,1) or even look here. There's good instructions for how to use ASD at that link.

There is a recovery partition on the HD but the only diagnostic tool is Disk Utility.

I'm downloading the ASD 3S132 now and will report back.

 

[DeltaMac]

You won't see the hardware test partition (if it even still exists).
The only way to find out if the hardware test is still available on the hard drive is to try to restart while holding the D key.
If that does not function (and you don't see any evidence of the test loading), then the hard drive has been erased (or replaced) at some point (and a re-format will remove it!) There's no way to recover it, either, other than figuring out how to make a bootable disk for the downloaded hardware test, if the original restore DVD has been lost.

Follow the steps to do that with the ASD that you download. It is a comprehensive diag test, used by Apple authorized service shops.

 

[b06tmm]

Follow the steps to do that with the ASD that you download. It is a comprehensive diag test, used by Apple authorized service shops.

Here are the tests that failed:

[12/19/17 12:21:15] Fan- ODD (test #4) - Turn On Automatically
- System turns on Motor and verifies Motor reaches min/max values, +/- 10 percent threshold
[12:23:45] ERROR -- 9 [Motor unable to stabilize between min and max limits] -- (143) TEST FAILED

[12/19/17 12:23:45] Fan- Hard drive (test #4) - Turn On Automatically
- System turns on Motor and verifies Motor reaches min/max values, +/- 10 percent threshold
[12:26:16] ERROR -- 9 [Motor unable to stabilize between min and max limits] -- (0) TEST FAILED

[12/19/17 12:26:53] Fan- ODD (test #7) - Turn On Automatically, Fans Full
- System turns on Motor and verifies Motor reaches min/max values, +/- 10 percent threshold, other fans full speed
[12:29:27] ERROR -- 9 [Motor unable to stabilize between min and max limits] -- (0) TEST FAILED

[12/19/17 12:29:27] Fan- Hard drive (test #7) - Turn On Automatically, Fans Full
- System turns on Motor and verifies Motor reaches min/max values, +/- 10 percent threshold, other fans full speed
[12:32:01] ERROR -- 9 [Motor unable to stabilize between min and max limits] -- (0) TEST FAILED

[12/19/17 12:37:55] Temp (TN0H) - (MacPro) IOH or (iMac or mac mini) MCP, HeatSink Temperature (test #1) - Sensor Reads Within Operating Range
- Check to ensure that sensor reads within operating range.
[12:37:55] ERROR -- 1 [Unable to read sensor] -- (-1.00) TEST FAILED

[12/19/17 12:37:56] SMC - 0x0: SMC PID Sensor check (test #1) - SMC PID Sensor check
- Checks the SMC PID Sensor warning counter that is monitoring sensors of each PID loop for erratic behaviour.
[12:37:56] ERROR -- 1 [The SMC's PID Sensor check has been tripped] -- TEST FAILED

[12/19/17 12:38:28] Thermal Interface - Processorrocessor0 (test #4) - TIM Test 75 percent GB
- Check that CPU heatsink is properly attached, using product spec theta dh + 75 percent guardband.
[12:38:51] ERROR -- 1 [Theta dh too high] -- TEST FAILED
[12/19/17 12:38:51] * 7 TEST(S) FAILED * [Elapsed time = 00:17:36]

 

[DeltaMac]

hmm...
two fans, reporting incorrectly (or outside of limits), and both of those also have the fan temp sensors with errors.
The line for TN0H is the heat sensor for a main chipset heat sink (on the Northbridge chip)
SMC PID sensor check fails, and finally:
CPU heatsink sensor reports that the CPU heatsink may not be properly attached.

If an SMC reset doesn't help, and you don't see anything on the main logic board that appears loose, or "dangle-y"
I would suggest that you disconnect the power supply, remove the coin battery from the logic board, let it set for an hour or two, then reassemble and test again.
Fails again, I would try a power supply.
If that doesn't help, then replace the logic board.
Of course, you could also try replacing both the hard drive and Optical fans, but I doubt that will change anything for the heatsink errors.
This would be a wonderful time to coincidentally be near a major city, where you might find an experienced board-level repair shop. I remember reading about one where you can send a logic board off for repair, but I have lost the link that I had for that. Maybe someone else will chime in with that knowledge.

I don't think I would use an iMac if the fans are not working correctly.

 

[b06tmm]

hmm...
two fans, reporting incorrectly (or outside of limits), and both of those also have the fan temp sensors with errors.
The line for TN0H is the heat sensor for a main chipset heat sink (on the Northbridge chip)
SMC PID sensor check fails, and finally:
CPU heatsink sensor reports that the CPU heatsink may not be properly attached.

If an SMC reset doesn't help, and you don't see anything on the main logic board that appears loose, or "dangle-y"
I would suggest that you disconnect the power supply, remove the coin battery from the logic board, let it set for an hour or two, then reassemble and test again.
Fails again, I would try a power supply.
If that doesn't help, then replace the logic board.
Of course, you could also try replacing both the hard drive and Optical fans, but I doubt that will change anything for the heatsink errors.
This would be a wonderful time to coincidentally be near a major city, where you might find an experienced board-level repair shop. I remember reading about one where you can send a logic board off for repair, but I have lost the link that I had for that. Maybe someone else will chime in with that knowledge.

I don't think I would use an iMac if the fans are not working correctly.

Thank you kindly for your help. I'm going to step away from this for a day or two and get my thoughts in order.

I'm doing this for a friend of mine that probably doesn't have the funds to repair/replace the power supply and logic board. I actually gave her this iMac when I got a 27" and now remember re-imaging it to make it minty fresh and that's why it no longer has the AHT.

It also developed a new problem while I was creating the ASD USB disk. The video all of a sudden became "washed out" and I can no longer do a PRAM/NVRAM reset - I never get the second chime and then it boots to the user. I can get the colors back to normal by putting the computer to sleep and waking it up. This only works once, then I have to unplug the computer to get it to work. Also, when running ASD the display is washed out.

Again, thank you for your time. I'm going to point her to this thread and see what she wants to do.

The initial problem she had maybe a year ago was her computer shutting down when watching videos. I looked at it back then and was able see it happen when using flash for videos. I wasn't adept at taking these things apart back then. She quit doing that and recently she had to unplug the computer before it would power on. Then it wouldn't power on at all. In hindsight I can now see that the heatsink for the on-board GPU had become detached then the fans had failed.

Cheers!

Tim