Thanks for the info. I'm finding that macfanctld is doing fine with the two temp sensors that it can grab info from in the meantime. Perhaps the fans are a little loud, but i'd rather that then frying another HDD (allegedly). There's been so much info in this thread, I'll have to go back and read about that temp sensor again. There IS one temp sensor taped to the HDD, that's the one that isn't grabbing a value - weird.

Radeon HD 2600 PRO - i figured. So, and please correct me if this isn't possible, can I install an older kernel and attempt to use the proprietary? Is that even possible? I'm going to do a quick google after this post. It's not that I wouldn't drop another dollar or two into this machine, but I just got laid off and I'm doing the best with low funds, and using what else I have around the house in the meantime.

I already took it apart to replace the bad (scorched?) HDD, i of course didn't have torx and used a perfectly sized flat head to take apart, however I won't be doing that again as it did cause a little damage to the fasteners and i had to lubricate the screws to put them back in effectively. I even had some left over - i forgot the two lcd connector screws - now they're taped to the back of the machine for when I get my torx set on the go again.

Have you ever had to mess around with the B43 driver? It's working for the wireless, but if i leave it for a bit it basically shits the bed and the interface has to be brought down/up again to start working again.

And that's the one that will get your temps/fan up high when it goes flaky. And on top of that, you cannot install ANY other hard drives other than Apple-blessed ones, since that proprietary sensor won't have anywhere to plug in to. The OWC sensor will get temps to normal, and let you use any hard drive/ssd you want to.
You *CAN* use an older kernel...if you're also willing to either downgrade everything and load an old version of Linux, or to compile your own, and deal with the gazillion problems you'll run in to using an old kernel on a new OS. Not to mention all the other modules you'll have to work with as well.

Personally, if funds are low, I'd live with the screen tearing until you can upgrade the hardware. eBay always has those older cards on sale.
Nope, but again, I replaced the stock Apple hardware with something else; you're probably still running the Apple wifi card in there, on a non-Apple OS. Not surprising you may have problems.

Personally, I think openSUSE is a good fit for iMac's, as I've had zero problems with it on several of them over the years.

1 members found this post helpful.

I just threw an old one i had around the house, i'm finding macfanctld an effective workaround for now, will be investigated more later with an SSD. I appreciate all the info on that matter. I've pasted an output of what macfanctld is doing currently at the bottom of this message, i don't think it picked up all the names of the temperature sensor mappings though...

Roger that. I think I will take your advice with the radeon screen tearing for now.

Yeah, screw that. I have a better wifi usb nub around here in the meantime.

Not ready to distro hop again quite yet, but if I do, then OpenSUSE is in the running.



(any ideas on how i format this nicely for reading on the forum?)

Using parameters:
temp_avg_floor: 45
temp_avg_ceiling: 55
temp_TC0P_floor: 50
temp_TC0P_ceiling: 58
temp_TG0P_floor: 50
temp_TG0P_ceiling: 58
fan_min: 2000
log_level: 2
Found applesmc at /sys/devices/platform/applesmc.768
Found 2 fans.
Found 13 sensors:
1: TA0P - ?
2: TC0D - CPU 0 Die Temp
3: TC0H - ?
4: TC0P - CPU 0 Proximity Temp
5: TG0D - GPU Die - Digital
6: TG0H - Left Heat Pipe/Fin Stack Proximity Temp
7: TG0P - GPU 0 Proximity Temp
8: TH0P - ?
9: TL0P - ?
10: TO0P - ?
11: TW0P - ?
12: Tm0P - Battery Charger Proximity Temp
13: Tp0P - ?
Speed: 4725, AVG: 51.2C, TC0P: 47.0C, *TG0P: 59.0C, Sensors: TA0P:24 TC0D:60 TC0H:56 TC0P:47 TG0D:76 TG0H:69 TG0P:59 TH0P:40 TL0P:36 TO0P:32 TW0P:39 Tm0P:50 Tp0P:76
Speed: 4725, AVG: 51.1C, TC0P: 47.0C, *TG0P: 59.0C, Sensors: TA0P:24 TC0D:59 TC0H:56 TC0P:47 TG0D:76 TG0H:69 TG0P:59 TH0P:40 TL0P:36 TO0P:32 TW0P:39 Tm0P:50 Tp0P:76
Speed: 4725, AVG: 51.1C, TC0P: 47.0C, *TG0P: 59.0C, Sensors: TA0P:24 TC0D:59 TC0H:56 TC0P:47 TG0D:76 TG0H:69 TG0P:59 TH0P:40 TL0P:36 TO0P:32 TW0P:39 Tm0P:50 Tp0P:76
Speed: 4725, AVG: 54.9C, TC0P: 47.0C, *TG0P: 59.0C, Sensors: TA0P:75 TC0D:59 TC0H:56 TC0P:47 TG0D:76 TG0H:69 TG0P:59 TH0P:40 TL0P:36 TO0P:32 TW0P:38 Tm0P:50 Tp0P:76
Speed: 4725, AVG: 50.9C, TC0P: 46.0C, *TG0P: 59.0C, Sensors: TA0P:24 TC0D:59 TC0H:56 TC0P:46 TG0D:76 TG0H:69 TG0P:59 TH0P:40 TL0P:36 TO0P:32 TW0P:38 Tm0P:50 Tp0P:76
Speed: 4725, AVG: 51.0C, TC0P: 47.0C, *TG0P: 59.0C, Sensors: TA0P:24 TC0D:59 TC0H:56 TC0P:47 TG0D:76 TG0H:69 TG0P:59 TH0P:40 TL0P:36 TO0P:32 TW0P:38 Tm0P:50 Tp0P:76
Speed: 4725, AVG: 51.0C, TC0P: 47.0C, *TG0P: 59.0C, Sensors: TA0P:24 TC0D:59 TC0H:56 TC0P:47 TG0D:76 TG0H:69 TG0P:59 TH0P:40 TL0P:36 TO0P:32 TW0P:38 Tm0P:50 Tp0P:76
Speed: 5250, AVG: 51.0C, TC0P: 46.0C, *TG0P: 60.0C, Sensors: TA0P:24 TC0D:59 TC0H:56 TC0P:46 TG0D:76 TG0H:69 TG0P:60 TH0P:40 TL0P:36 TO0P:33 TW0P:38 Tm0P:50 Tp0P:76
Speed: 5250, AVG: 51.1C, TC0P: 47.0C, *TG0P: 60.0C, Sensors: TA0P:24 TC0D:59 TC0H:56 TC0P:47 TG0D:76 TG0H:68 TG0P:60 TH0P:40 TL0P:36 TO0P:33 TW0P:38 Tm0P:50 Tp0P:76
Speed: 4725, AVG: 51.0C, TC0P: 47.0C, *TG0P: 59.0C, Sensors: TA0P:24 TC0D:59 TC0H:56 TC0P:47 TG0D:76 TG0H:69 TG0P:59 TH0P:40 TL0P:36 TO0P:32 TW0P:38 Tm0P:50 Tp0P:76
Speed: 4725, AVG: 51.0C, TC0P: 47.0C, *TG0P: 59.0C, Sensors: TA0P:24 TC0D:59 TC0H:56 TC0P:47 TG0D:76 TG0H:69 TG0P:59 TH0P:40 TL0P:36 TO0P:32 TW0P:38 Tm0P:50 Tp0P:76
Speed: 4725, AVG: 50.9C, TC0P: 47.0C, *TG0P: 59.0C, Sensors: TA0P:24 TC0D:58 TC0H:56 TC0P:47 TG0D:76 TG0H:69 TG0P:59 TH0P:40 TL0P:36 TO0P:32 TW0P:38 Tm0P:50 Tp0P:76

etc...

It's on the side of the drive it doesn't plug into it..I just put a WD Black 1TB into an iMac of this era about 3 weeks ago. easy peezy lemon squeezy

UPDATE - I found a better utility for controlling the fans on the iMac, it's called mbpfan (https://github.com/linux-on-mac/mbpfan), macfanctld was fine but upon closer examination it was only really adjusting two of the fans (the ones default named HDD and ODD - i believe these are the two main fans in the bottom - left and right respectively) but not the CPU fan.


Here's my guide to installing mbpfan - note: I'm using Linux Mint 19 (can't see why it won't work for debian/ubuntu)

#i checked for the two dependencies for mbpfan
lsmod | grep -e applesmc -e coretemp


#install mbpfan
apt install mbpfan


#listed contents of configuration file
cat /etc/mbpfan.conf



#as per the comments i needed to run two commands to determine min and max value for fans.

#command #1 minimum
cat /sys/devices/platform/applesmc.768/fan*_min

#output
4000
4000
1200

#the configuration file advised that i use the lowest value here for minimum, but i suggest that you use the highest value, as each of these lists the minimum speed a fan should be running at in my understanding - ie. 4000

#then command #2 maximum
cat /sys/devices/platform/applesmc.768/fan*_max

#output
5100
6000
3900


#the configuration file advised that i use the highest value here for maximum, and i agree - ie. 6000

#opened config file for editing
nano /etc/mbpfan.conf

#edited contents
[general]
# see https://ineed.coffee/3838/a-beginner...n-under-ubuntu for the values
min_fan_speed = 4000 # put the *lowest* value of "cat /sys/devices/platform/applesmc.768/fan*_min"
max_fan_speed = 6000 # put the *highest* value of "cat /sys/devices/platform/applesmc.768/fan*_max"
low_temp = 63 # try ranges 55-63, default is 63
high_temp = 66 # try ranges 58-66, default is 66
max_temp = 86 # take highest number returned by "cat /sys/devices/platform/coretemp.$
polling_interval = 7 # default is 7 seconds


#in my case stopped and disabled 'macfanctld' - you may not need to do this if your were not using a previous mac fan control service/software
systemctl stop macfanctld
systemctl disable macfanctld

#started and enabled mbpfan
systemctl start mbpfan
systemctl enable mbpfan


#Used sensors to check that it's working
sensors

#output
applesmc-isa-0300
Adapter: ISA adapter
ODD : 4002 RPM (min = 4000 RPM, max = 5100 RPM)
HDD : 4004 RPM (min = 4000 RPM, max = 6000 RPM)
CPU : 4001 RPM (min = 1200 RPM, max = 3900 RPM)
TA0P: +20.8°C
TC0D: +30.8°C
TC0H: +33.5°C
TC0P: +36.0°C
TG0D: +47.5°C
TG0H: +43.0°C
TG0P: +45.0°C
TH0P: +38.8°C
TL0P: +35.2°C
TO0P: +35.0°C
TW0P: -128.0°C
Tm0P: +36.2°C
Tp0P: +70.8°C

radeon-pci-0100
Adapter: PCI adapter
temp1: +45.0°C

coretemp-isa-0000
Adapter: ISA adapter
Core 0: +33.0°C (high = +105.0°C, crit = +105.0°C)
Core 1: +33.0°C (high = +105.0°C, crit = +105.0°C)


#Looks like it's working.