Is It Worth Repairing a 2017 iMac With Frequent, Irritating and Undiagnosable Kernel Panics?

[Buadhai]

You could try installing Macs Fen Control (it's free) and see if you can bring those temps down or if it reports a failed sensor or fan.

I installed Macs Fan Control. At the moment, it's 7:30AM and the room temperature is 29ºC. The memory temperature is 49ºC and the fan is running at 1200 RPM.

And, there's this:

**** SMC sensors ****

CPU Thermal level: 0
IO Thermal level: 0
Fan: 1196 rpm
CPU die temperature: 58.67 C
CPU Plimit: 0.00
GPU Plimit (Int): 0.00

I'll keep watching it.

Yesterday, there was no kernel panic and the room temperature was 35ºC. It's going to be cooler today.

He did mention that his problems began right after he upgraded to 12.4. ...

Actually the first panic was the day before I upgraded to 12.4; when I was still running 12.3

On one hand I get advice that I should wipe and restore, which indicates that those giving the advice think it's a software problem

On the other hand, I get other advice that it must be a hardware problem.

Right now I'm inclined to just let it go.

 

[fritters1]

I was having several panics a day and tried many things for many weeks to no avail. I finally solved it by wiping the SSD and installing a fresh copy of the OS. Since then, all has been great. No panics and it even fixed a few other glitches I had been experiencing. I had been updating the OS for several years so a clean install was in order.

I literally just registered after having read this forum for a long time just to second this.

As unlikely as it seemed, exactly this, a clean install of 12.4, solved my hourly kernel panic reboots on my 2017 27" iMac that had started occurring about 2-3 months ago. I had tried using safe mode and re-installing to no avail.

Now everything is fine and the iMac (FusionDrive 2TB) feels faster than ever as I'm not sure whether I had ever done a clean install since 2009.

So don't give up just yet.

 

[Buadhai]

It was suggested that excessive heat might be causing RAM failures or otherwise account for the panics. I decided to use a few tools to check this.

As mentioned above, I installed Macs Fan Control. I also have iStat Menus which can display a history of things like RAM temperature and fan speed.

I also ran this command and directed the output to a file:

sudo powermetrics --samplers thermal

Some results:

The powermetrics command shown above returns the thermal pressure level of the machine. Apple's documentation of this is contradictory, but the "normal" level is called Nominal. The level above that is referred to as either Fair or Moderate. Levels of higher thermal pressure are Heavy and worse.

I ran this continuously from about 10:30 this morning until 2:00 this afternoon. At no time did the pressure level go higher than Moderate: 1439 Nominal readings and 1261 Moderate readings. In other words, the temperate pressure never reached critical levels even though the ambient temperate in my computer room is now 34.4ºC (94ºF)

Here are some charts from iStat Menus showing the fan speed and RAM proximity temperature for the hour from 2:00 to 3:00, the hottest hour of the day.

FAN SPEED

RAM (Memory) Proximity.

I have no idea what was going on when both the temperature and fan speed peaked. I was in a very hot kitchen preparing Burmese pork curry. But, even at that time the thermal pressure was reported as Moderate.

My impression here is that the machine is operating normally and even on a very hot day the RAM temperature and fan speed are at acceptable levels and not likely to shut the machine down.

Another consideration is that most of the kernal panics happen when the ambient temperature is much less than it is now. Of the last ten panics, only three happened during the heat of the day. The rest were in the morning or evening.

 

[Buadhai]

I literally just registered after having read this forum for a long time just to second this.

As unlikely as it seemed, exactly this, a clean install of 12.4, solved my hourly kernel panic reboots on my 2017 27" iMac that had started occurring about 2-3 months ago. I had tried using safe mode and re-installing to no avail.

Now everything is fine and the iMac (FusionDrive 2TB) feels faster than ever as I'm not sure whether I had ever done a clean install since 2009.

So don't give up just yet.

I've been running Macs since 1984. Not once since then have I ever had to wipe a drive, reinstall and restore. I have booted in to recovery mode to reinstall the OS, but never did a wipe and restore. I guess there's always a first time, but I hate to break a nearly 40 year record.

As an aside, when I was working for the US Feds, the support people constantly forced us to do this on our Windoze machines. They would give you fifteen minutes. If they couldn't fix the problem by then, it was wipe the drive and restore from a ghost drive. I hated that because you didn't learn anything. I guess that's why I still balk at doing it.

 

[Fishrrman]

Even though the RAM is original, you might consider taking the DIMMs out and then "re-seating" them. Just to make sure it's not a "bad contact" somewhere with the RAM...

 

[rovostrov]

I've been running Macs since 1984. Not once since then have I ever had to wipe a drive, reinstall and restore. I have booted in to recovery mode to reinstall the OS, but never did a wipe and restore. I guess there's always a first time, but I hate to break a nearly 40 year record.

As an aside, when I was working for the US Feds, the support people constantly forced us to do this on our Windoze machines. They would give you fifteen minutes. If they couldn't fix the problem by then, it was wipe the drive and restore from a ghost drive. I hated that because you didn't learn anything. I guess that's why I still balk at doing it.

I've never had to do it either but it did fix my issues. I had been updating since 2015 and it seems the last year of security & firmware updates is what caused havic for my system. Good luck, hope you figure it out

 

[whitby]

This has been mentioned but even Apple memory has been known to go faulty (I had a 2012 iMac with precisely this problem and it was a bad memory stick). In fact I had a system with 2 sticks of Apple and 2 sticks of OWC and one of the Apple sticks failed.

There are 4 slots in the iMac, if all 4 slots are occupied, remove 2 of them and reboot. You should remove them in pairs as the processor uses dual channel memory, so remove 1 and 2 or 3 and 4 (Slot 1 is towards the top of the machine). If you remove 1 and 2 move 3 and 4 to slots 1 and 2. You can keep swapping them around until you have used all memory sticks in the system. If you are lucky one of the combinations will cause the problem and the others will not. If you have only 2 sticks, you can remove one, it will run but less optimally. Remove 1 and put 2 in its place or remove 2. Again if you are lucky the system will kernel panic on 1 of the combinations only. It is rare for more than 1 stick to go faulty but it can happen. Just make sure you have a stick in slot 1 when you try out the various combinations.

BTW if you have an iMac with 4GB Apple sticks installed they will not work with other memory of 8GB or more. I had a system with 2 x 4GB sticks and I added 2 x 16GB for a total of 40GB and it kept kernel panicking. I took it into Apple and they removed the Apple memory and it worked fine. They then told me about this "little" issue.

BTW in all cases the system passed the built in Apple hardware test and the Memtest utility.

Upgrading the OS can change memory usage so it is not uncommon for an OS upgrade to trigger a memory failure and memory failures are very prone to random occurrences. I would not give up yet. Of course if all that fails, then you probably have a bad motherboard and then it is up to you. I have a 2017 27" iMac as one of my machines and it has OWC memory (I ordered it with 8GB of Apple memory, discarded it and replaced with 4 16 GB sticks of OWC memory for a total of 64 GB) and it has never failed. And it gets a lot of hard use. It is a good machine and worth keeping unless it is truly dead....

 

[Buadhai]

If you have only 2 sticks, you can remove one, it will run but less optimally. Remove 1 and put 2 in its place or remove 2. Again if you are lucky the system will kernel panic on 1 of the combinations only. It is rare for more than 1 stick to go faulty but it can happen. Just make sure you have a stick in slot 1 when you try out the various combinations.

My iMac has two RAM slots:

Your Mac contains 2 memory slots, each of which accepts
a 2400 MHz DDR4 SO-DIMM memory module.

Each now has 8GB Apple RAM.

As I mentioned, I have read the iFixit article which says that opening the iMac involves 64 steps, takes 1 to 2 hours and requires a number of special tools.

I have neither the tools nor the skill to do this on my own. This means I'd have to take this into a shop every time I tried a new combination. And, once I remove one stick, how long do I wait before I decide that the stick I removed was causing the panics? Since the panics started I've gone as long as ten days without one.

So, this means three trips to the shop: One to remove one stick. One to remove the other stick. One to put both sticks back and, perhaps, replace a faulty stick. And, I'd have to be doing this over a period of twenty days or more.

If I were having many panics per day, this might be worth the trouble and expense. But, given that the panics have become rather few and far between, it just doesn't seem worth it.

 

[Buadhai]

Anyone still here and interested in a more detailed analysis of this series of kernel panics is urged to read the first answer to my question on Ask Different: How to diagnose too many kernel panics...

tl;dr - Here's pertinent part of the conclusion offered by the only person, pion, to respond to my Ask Different question:

And yet, despite these important clues, we simply don't have enough information or debugging tools available to get any more granular data on what the cause could be. MCE root causes span the entirety of hardware, firmware, and software – a bug in any of those can manifest as an MCE. Due to the low-level nature of MCEs and the fact that they halt CPU execution, the amount of useful diagnostic data that is able to be collected from a closed system at runtime from this generation Intel core is very limited (as compared to an "ordinary" kernel panic, when the CPU continues to fetch & execute instructions and xnu is often able to continue running to significant extent, allowing for interactive debugging).

And, yeah, it took me a long time to fully understand what pion was saying. But after lots of re-reading and research, I think I finally do.

 

[whitby]

My iMac has two RAM slots:



Each now has 8GB Apple RAM.

As I mentioned, I have read the iFixit article which says that opening the iMac involves 64 steps, takes 1 to 2 hours and requires a number of special tools.

I have neither the tools nor the skill to do this on my own. This means I'd have to take this into a shop every time I tried a new combination. And, once I remove one stick, how long do I wait before I decide that the stick I removed was causing the panics? Since the panics started I've gone as long as ten days without one.

So, this means three trips to the shop: One to remove one stick. One to remove the other stick. One to put both sticks back and, perhaps, replace a faulty stick. And, I'd have to be doing this over a period of twenty days or more.

If I were having many panics per day, this might be worth the trouble and expense. But, given that the panics have become rather few and far between, it just doesn't seem worth it.

My bad, I assumed you had a 27” iMac not the 21.5” which has, as you, say 2 slots and requires you to open the case each time. The 27” has 4 slots and is easily accessible via a hatch on the rear of the machine. Apologies I either misread your post or forgot.

 

[Buadhai]

My bad,

No worries.

 

[Buadhai]

At this point I'm not really sure what to do.

I live in northeast Thailand. The only two Apple stores in the country are in Bangkok, about 250K from where I live.

There is a local authorized Apple service center, but I don't trust them much. I'm fairly confident that if I take it to them they will conclude that the only solution is to replace the motherboard.

I'm not convinced that the expense of replacing the motherboard is worth it on a five year old machine. Especially after I've played a bit with my wife's M1 iMac.

Edit: I did finally get Universal Control to work between my iMac and my iPad using my Logitech mouse. But couldn't get it to work between my wife's iMac and my iMac.

 

[mollyc]

i did not have kernel panics but my 2017 27” imac kept having random shutdowns last year and my husband replaced the power supply and i’ve had zero issues since.

 

[Buadhai]

I decided that I would try the wipe-reinstall-restore song and dance that several people have recommended.

I booted in to recovery mode, but was surprised to see that my Logitech BT mouse doesn't work and that the arrow keys on my Logitech USB keyboard don't work. (The Enter key works, but that's it.)

Does that mean that to use recovery mode I'm going to have to purchase a wired mouse and a different keyboard?

BTW, I tried to set up Universal Control thinking I might use the Magic Mouse from my wife's M1 iMac, but couldn't get that to work. I was signed in to both computers with the same Apple ID. The two computers are only about two meters apart and both are connected to the same WiFi network and have BlueTooth enabled. Both machines have Handoff enabled and both have Universal Control enabled. I just couldn't get it to work. What am I missing?

 

[DeltaMac]

If only your arrow keys don't work on the keyboard -- if you get a mouse that works, why would you need to use the arrow keys on the keyboard?
Always a Good Thing™ to have input devices that work, regardless of how you are booting... I think I get complacent with always having a spare device that I can use. I must have 5 or 6 usable wired USB keyboards, and maybe 10 wired mouses. Only have one wireless, an Apple magic mouse, which I seldom need to use.

 

[Buadhai]

If only your arrow keys don't work on the keyboard -- if you get a mouse that works, why would you need to use the arrow keys on the keyboard?

Since I don't have a mouse that works I was hoping I could navigate through Recovery Mode using the arrow keys on the keyboard. That didn't work and neither did Universal Control so I guess I need to buy a wired USB mouse.

 

[Buadhai]

I found my old Magic Mouse at the back of a drawer. The touch features don’t work anymore, so it operates as a one button mouse. But, it did get me through recovery mode. I reformatted the drive and reinstalled Monterey. After boot. I was offered Migration Assistant. I chose to restore from today’s CCC backup which resides on a Samsung T7 external SSD.

The machine rebooted and I was asked, again, all the questions about region, language, keyboard, etc. Why twice for all those?

From there it went here:

Where I’ve been stuck for four hours.

Does it really take that long, or should I abort?

 

[Buadhai]

OK, it’s now been seven hours of "Transferring Your Information".

How long is it going to take?

 

[mollyc]

Are you on wifi or ethernet? wifi might take awhile, depending on your connection speeds and amount of data. ethernet takes a couple of hours.

 

[rovostrov]

I found my old Magic Mouse at the back of a drawer. The touch features don’t work anymore, so it operates as a one button mouse. But, it did get me through recovery mode. I reformatted the drive and reinstalled Monterey. After boot. I was offered Migration Assistant. I chose to restore from today’s CCC backup which resides on a Samsung T7 external SSD.

The machine rebooted and I was asked, again, all the questions about region, language, keyboard, etc. Why twice for all those?

From there it went here:

View attachment 2025733

Where I’ve been stuck for four hours.

Does it really take that long, or should I abort?

I think the time it takes will depend on how much data you are transferring. I have an older macbook pro and it is really slow transferring info from an external. I'd give it a few more hours to see if there is any progress. I've personally never trusted migration assistant which is why I recommended the manual move of your files/data. My fear is that migration assistant would transfer the same problem/issue that was originally causing the panic. Here is an article that might help if it appears to be stuck https://mactakeawaydata.com/migration-assistant-stuck/

 

[Buadhai]

After seven hours I decided nothing was happening, so I cancelled the process. The machine rebooted. The previous ordinary users were created, but nothing at all had been migrated. When I logged in I was faced with an empty desktop, a non-functional dock and no menubar. Clicking icons in the dock did nothing. So, I used the power button to reboot. This time I got a functioning UI, but it was very clearly that nothing had been migrated: no apps, no data. So, I opened Migration Assistant and tried again. This time I got a proper migration progress window:



This time the projected time was reasonable considering I was migrating from an SSD attached to the Mac (no WiFi or Ethernet involved). I went to sleep before the migration was finished.

When I got up this morning it was done. I had to jump through a bunch of hoops enabling various apps to do this and that via System Preferences. And, just as I was finishing that up

ANOTHER KERNEL PANIC!

So, the whole miserable exercise of wiping the drive, reinstalling the OS and migrating from a back up turned out to be a complete, total and very annoying waste of time.

I guess I missed the comment by @rovostrov about manually moving the files. But, that would have taken days. (But, how would manually moving the files keep me from manually copying a file that was causing the problem? How do you know if you're manually moving a possibly corrupt file?)

I give up.

 

[Buadhai]

For those of you who haven't gone through the wipe-reinstall-restore song and dance (as I hadn't) here are a few of the things I did (and continue to do) to get the machine running as I want it:

• Reinstall DropBox, reauthorize, remove "old" computer and add "new" computer. (DropBox still not working properly.)

• Uninstall and reinstall BackBlaze. Reauthorize. Take the steps necessary for my "new" computer to inherit the backup state of my "old" computer.

• Reinstall Karabiner. Reauthorize. Verify settings

• Reauthorize Logi Options and verify mouse settings.

• Reactivate CCC jobs and verify settings of each job.

• Reenable: File Sharing, Remote Login (my remote SSH tunnels were all broken), Printer Sharing

• Figure out why MacPorts is generating this warning on some ports: "Warning: Error parsing file"

Many other apps needed "Security & Privacy" authorizations

To put it mildly, it's been a real PITA morning.

 

[Buadhai]

I was having several panics a day and tried many things for many weeks to no avail. I finally solved it by wiping the SSD and installing a fresh copy of the OS. Since then, all has been great. No panics and it even fixed a few other glitches I had been experiencing. I had been updating the OS for several years so a clean install was in order.

Well, this has been a complete disaster. I went from having a machine that had kernel panics five to ten times a week to one that now has many, to the point where the machine become unusable. So, from useable machine to unusable machine. Plus, I spent the better part of two days making the disaster happen; all by myself.

Here's todays panic count and it's not even noon yet:

Kernel-2022-07-04-043549.panic
Kernel-2022-07-04-063322.panic
Kernel-2022-07-04-093528.panic
Kernel-2022-07-04-093902.panic
Kernel-2022-07-04-101554.panic
Kernel-2022-07-04-101755.panic

Sometimes when it reboots, there is no menu bar and it is impossible to enter text. The keyboard works, but you can't enter text into any app. The only solution is to reboot using the power button. (Of course, those many reboots don't show up as kernel panics.)

So, I guess my decision has been made: buy a new machine

I'm glad it worked for you @rovostrov, but it has been a major mess for me.

 

[Nguyen Duc Hieu]

So, I guess my decision has been made: buy a new machine

I'm glad it worked for you @rovostrov, but it has been a major mess for me.

And what would you do with your Kernel-panic iMac?

 

[Buadhai]

And what would you do with your Kernel-panic iMac?

Probably give it to a teacher I know who is happy to have stuff like that for his students to tinker with. Also, my sister-in-law works for a university that is happy to receive unused electronic stuff.