2020 iMac Constant Kernel Panic Crashes whenever using 2nd Monitor

[JVKay]

So I see that I am not the only one with this issue.

I just had to most arrogant and rude Apple advisor push on me that my monitor was the issue yet I've used it on a different mac and it's always been working wonderfully!

I too have a iMac 2020 i7 with the MD Radeon Pro 5500 XT 8 GB. and I have experience these crashes for a while when I have the 2nd monitor but that advisor refused to believe that it was an issue with the mac itself. Always our fault, never theirs.

Sorry to hear that - I am stunned Apple hasn’t owned up to this yet. As for me it’s been a week with the second monitor removed and no shutdowns. I feel like this is the kind of situation the auto industry faces when they have to do recalls: a faulty part causing various problems across the spectrum of the model concerned.

I still haven’t decided on trying a second monitor.

 

[depesperatemacuser]

Sorry to hear that - I am stunned Apple hasn’t owned up to this yet. As for me it’s been a week with the second monitor removed and no shutdowns. I feel like this is the kind of situation the auto industry faces when they have to do recalls: a faulty part causing various problems across the spectrum of the model concerned.

I still haven’t decided on trying a second monitor.

I've worked without the second monitor for a couple days without crashes.. but this is reducing my productivity for work, I used to work with 2 extra monitors, I had to reduce to 1 to work from home. I didn't fork 3500$ for a brand new mac to find myself with a computer that doesn't perform well. it's 2017 predecessor did it without any issue. The adviser barely let me talk, she was not listening, for her the monitor was faulty, I would have to contact the manufacturer of the monitor, make sure all firmware are up to date, try another monitor, but I have seen so many people with different monitors that had the same exact KP issue. She just said that if the computer was running fine when the monitor was not plugged in so it was the monitor. meanwhile there isn't anything plugged in the thunderbolts.. so of course if this was the issue, I wouldn't know if there isn't anything plugged in to try. Not sure what I can plug in that port instead of the monitor, to see if it's going to crash.

 

[JVKay]

I've worked without the second monitor for a couple days without crashes.. but this is reducing my productivity for work, I used to work with 2 extra monitors, I had to reduce to 1 to work from home. I didn't fork 3500$ for a brand new mac to find myself with a computer that doesn't perform well. it's 2017 predecessor did it without any issue. The adviser barely let me talk, she was not listening, for her the monitor was faulty, I would have to contact the manufacturer of the monitor, make sure all firmware are up to date, try another monitor, but I have seen so many people with different monitors that had the same exact KP issue. She just said that if the computer was running fine when the monitor was not plugged in so it was the monitor. meanwhile there isn't anything plugged in the thunderbolts.. so of course if this was the issue, I wouldn't know if there isn't anything plugged in to try. Not sure what I can plug in that port instead of the monitor, to see if it's going to crash.

I have a drive in the other Thunderbolt port and no problems. B&H said the same thing about making sure I had the most up to date
drivers for the monitor but I haven’t bothered with that yet. I think we can forget about Apple helping.

 

[raging_dictor]

Ive had this for 15 months. Had two login board replacements and the issue persists.
Only happens when external display is plugged into usb-c port or the computer has been sleeping for a while.

Latest Kernel panic:
CPU Machine Check Architecture Error Dump (CPU: UNKNOWN, CPUID: 0x80000009000A0655)
Core: 0
IA32_MC3_STATUS=0xBE00000000800400
IA32_MC3_CTL=0x0
IA32_MC3_ADDR=0xFFFFFF7FACD2EF07
IA32_MC3_MISC=0xFFFFFF7FACD2EF07
Core: 0
IA32_MC4_STATUS=0xFE00000000800400
IA32_MC4_CTL=0x0
IA32_MC4_ADDR=0xFFFFFF7FACD2EF07
IA32_MC4_MISC=0xFFFFFF7FACD2EF07
Core: 0
IA32_MC11_STATUS=0xEE0000000040110A
IA32_MC11_CTL=0x0
IA32_MC11_ADDR=0xFF71EC00
IA32_MC11_MISC=0x47880000086
Core: 0
IA32_MC12_STATUS=0xEE0000000040110A
IA32_MC12_CTL=0x0
IA32_MC12_ADDR=0xFF71CB80
IA32_MC12_MISC=0x4B880000086
Core: 0
IA32_MC13_STATUS=0xEE0000000040110A
IA32_MC13_CTL=0x0
IA32_MC13_ADDR=0xFF71CBC0
IA32_MC13_MISC=0x4B880000086

Mac specs:

 

[AAPLGeek]

Ive had this for 15 months. Had two login board replacements and the issue persists.
Only happens when external display is plugged into usb-c port or the computer has been sleeping for a while.

Latest Kernel panic:
CPU Machine Check Architecture Error Dump (CPU: UNKNOWN, CPUID: 0x80000009000A0655)
Core: 0
IA32_MC3_STATUS=0xBE00000000800400
IA32_MC3_CTL=0x0
IA32_MC3_ADDR=0xFFFFFF7FACD2EF07
IA32_MC3_MISC=0xFFFFFF7FACD2EF07
Core: 0
IA32_MC4_STATUS=0xFE00000000800400
IA32_MC4_CTL=0x0
IA32_MC4_ADDR=0xFFFFFF7FACD2EF07
IA32_MC4_MISC=0xFFFFFF7FACD2EF07
Core: 0
IA32_MC11_STATUS=0xEE0000000040110A
IA32_MC11_CTL=0x0
IA32_MC11_ADDR=0xFF71EC00
IA32_MC11_MISC=0x47880000086
Core: 0
IA32_MC12_STATUS=0xEE0000000040110A
IA32_MC12_CTL=0x0
IA32_MC12_ADDR=0xFF71CB80
IA32_MC12_MISC=0x4B880000086
Core: 0
IA32_MC13_STATUS=0xEE0000000040110A
IA32_MC13_CTL=0x0
IA32_MC13_ADDR=0xFF71CBC0
IA32_MC13_MISC=0x4B880000086

Mac specs: View attachment 1925035

Could be unrelated but have you tried taking out the original 8GB RAM and only keeping the matched 16GB pair?

 

[raging_dictor]

Could be unrelated but have you tried taking out the original 8GB RAM and only keeping the matched 16GB pair?

Yes. I was even told to place the Ram in specific slots but that didn’t change a thing. I’ve tried only default ram, only upgraded, one of each… still persists

 

[raging_dictor]

So I just updated to the latest Monterey 12.1 which was available as of the date of this message. I thought id plug my screen in again to see if the update fixed the crash, and as soon as I connected the display a notification appeared in the top right hand screen. Ive attached the notification as an image. This has never showed up before. I unplugged the device, and plugged it back in and the message showed again. I repeated the process again and it stopped showing up. I will use the display now and update you all if it crashes again.

 

[Ross Brandt]

So I just updated to the latest Monterey 12.1 which was available as of the date of this message. I thought id plug my screen in again to see if the update fixed the crash, and as soon as I connected the display a notification appeared in the top right hand screen. Ive attached the notification as an image. This has never showed up before. I unplugged the device, and plugged it back in and the message showed again. I repeated the process again and it stopped showing up. I will use the display now and update you all if it crashes again.

Ok, I'm going to try that as well. I've been crashing 1-2x per day with external monitors plugged in. Doesn't matter which monitor. Just bought this mac as an alternative to the newer T1 Chipped varieties, and I'm bummed that I can't do my work with my external monitor. Like a lot of folks I'm video editor / graphic designer. I'll check back with news as well.

 

[carrinli]

Hi all. I am having this same issue even after upgrading to Monterey 12.1 (specs screenshot attached). I use Logic Pro/Adobe Products and receive consistent kernel panics with an external monitor. I brought my machine into the genius bar a couple months ago, but all they did was wipe the machine. From what I'm reading, it sounds like the Radeon Pro 5500XT 8GB is the culprit. Has anyone been successful in getting Apple to fix this?

 

[Ross Brandt]

Yeah all crashing stops when the external is unconnected. VERY disappointed. Didn't realize how spoiled I was I guess.

 

[abad0n]

I have the same issue with my 2020 iMac with 5500XT 8GB. I finally tried to figure it out myself, after listening to Apple Support to reinstall/uninstall/run safe mode etc. I got Dell D6000 external docking station with DisplayLink and connected external monitor to it. After that for at least > 24h of testing now - no kernel panics, when before it usually happen every 3-5h. I know it is not a fix, but I cross my fingers I will be able to use 2nd monitor with this iMac finally.

 

[Ross Brandt]

My Mac repair shop (Onyx Consulting) has asked me to bring my iMac in for hardware diagnostics as they think it's a CPU failure. I'll report back. I did have better luck (less crashes) using a new cable connector and a slightly more modern external monitor: https://smile.amazon.com/DisplayPor...&sprefix=usb-c+to+display,aps,353&sr=8-4&th=1 But after about a day, it panicked but differently than before. It's only panicked three times since Jan 10, but that is 3x too many imho.

 

[gak1005]

I'm experiencing the same problem and I also have the 2020 iMac with 5500XT. Starting to get really tired of having to talk to apple advisors who tell me the same thing over and over again. That being said, they keep insisting that I should upgrade to OS Monterey as a number one trouble shooting step which I understand, but I see many people with more updated OS version than mine still experiencing the same problem. (I'm on the latest version of Catalina) I wonder if I should even attempt it and hope it will magically fix everything? I'm a little concerned about my programs not being able to transition well over to the new MacOS, and trying to prevent risking anything at the moment.

Also, I'm curious what display port are you guys using for the external monitor? I'm using usb-c to HDMI right now, and I was starting to wonder if a usb-c to usb-c display port might have a better chance.

 

[abad0n]

So, an update for kernel panics with Dell D6000 external docking. No kernel panics so far. Meaning it can be used like that.

 

[gak1005]

So, an update for kernel panics with Dell D6000 external docking. No kernel panics so far. Meaning it can be used like that.

Wow some hope finally. Congrats and thanks for updating!

 

[abad0n]

my iMac is running with d6000 for few days with external monitor, and I did not experience any kernel panics so far. So what I can suggest, get external dock and use external monitors with it.

 

[raging_dictor]

my iMac is running with d6000 for few days with external monitor, and I did not experience any kernel panics so far. So what I can suggest, get external dock and use external monitors with it.

I tried this with a Thinkpad usb c external dock. It happened just as frequently. I tried a belkin dock at another point and had the same issue.

I bought my Mac to an apple store in the UK and requested to speak to the store manager. I bought it in August 2020 and I just managed to get a FULL refund in January 2022. I explained all the issues I was having and how I first made them aware of the issue only days after I first purchased the Mac. I quoted my consumer rights and explained how I had given them multiple chances to fix the Mac (it had 2 logic board replacements in an attempt to fix this) but nothing worked. They offered me an exchange on a brand new Mac (same model) then I showed them this forum, plus many more on the apple developer forums and showed them that this was not just an issue with my Mac. After much deliberation, I was offered a full refund and I took immediately. I also was refunded the total cost of the apple care I purchased.

Im extremely disappointed with apple. Having to deal with their "tech support" was by far the worst experience I have ever had with apple. Constantly being told to wipe my Mac over and over and over again expecting a different result each time... it almost broke me.

 

[carrinli]

I've tested with two different monitors, one usb-c to DVI and the other usb-c to Thunderbolt 2. Had the same panics with both. I have not had a single panic when using my computer without an external monitor. I'd really love to get Apple to fix/refund rather than buy an external dock! Thanks all for sharing.

I'm experiencing the same problem and I also have the 2020 iMac with 5500XT. Starting to get really tired of having to talk to apple advisors who tell me the same thing over and over again. That being said, they keep insisting that I should upgrade to OS Monterey as a number one trouble shooting step which I understand, but I see many people with more updated OS version than mine still experiencing the same problem. (I'm on the latest version of Catalina) I wonder if I should even attempt it and hope it will magically fix everything? I'm a little concerned about my programs not being able to transition well over to the new MacOS, and trying to prevent risking anything at the moment.

Also, I'm curious what display port are you guys using for the external monitor? I'm using usb-c to HDMI right now, and I was starting to wonder if a usb-c to usb-c display port might have a better chance.

 

[choreo]

It is not just the iMac! I have had the same problems with my 2019 MacPro since Day-One (July 2020)! First bad experience I have ever had with an Apple product in 30 years - sorry I ever bought it!

It has happened throughout Catalina versions all the way through the last Big Sur version released (still running that version). I have always had Adobe Photoshop, Illustrator, After Effects, Bridge, Acrobat Pro, InDesign and Dreamweaver installed (and reinstalled). Adobe definitely triggers the issue, but I have Kernal Panics sometimes several a day to sometimes 5 days apart. I run the same 3 External 27" NEC displays I used with my previous MacPro for 8 years with no issues.

I ran all the same software on my old 2012 MacPro for 8 years without a single freeze, shutdown or auto-restart and the same 3 displays the last year I had it! My new M1 16" MacBook Pro is also running the same software without a single problem.

In my case, I finally decided it was a problem with the Radeon w5700x card architecture and/or drivers (maybe together with the T2 chip?). Other threads on the forum in the past said they had the same problems with that Apple MacPro/GPU configuration and several claimed when they gave up and spent a few thousand dollars more to replace with a Vega GPU, their problems disappeared. After many sessions with Apple Support in the beginning, they finally decided it was the main logic board (I doubted that assessment), so even after 4+ months, they agreed to ship me a brand new 2019 MacPro with the same config. As soon as I booted up and installed my software - same problems started (as expected). I asked Apple if they would send me a Vega GPU just to "try" to see if that was the source and the answer was "No", so I am still fighting with the problem 1-1/2 years later! They apparently have no interest in pinning down the source. I personally think there is just an incompatibility between the 5700 GPU, Apple and Adobe. However, I am also getting auto-restarts now with only Safari or Quicktime running. I do some fairly intensive work jumping between Photoshop, AI and InDesign with big documents usually with no issues. I usually often have crashes in Adobe Dreamweaver while actually using it now.

The problem also is somehow/sometimes tied to "sound"? Several times when I experienced a freeze while working, I would hear a rhythmic static pulsing through the speakers and the cursor would freeze followed by a restart? I have not seen that behavior since Big Sur, but now sometimes when trying to watch a Quicktime tutorial or even a video link in iChat yesterday, the entire 15-30 minute video will play entirely through in 2 seconds with no sound. If I force quit "CoreAudio" in Activity Monitor - forcing it to relaunch, the videos will play fine with sound as well? Restarting the computer restarts CoreAudio and also fixes the problem for a while.

Another strange thing I see after a panic/auto-restart is if any applications were open at the time of the crash, the Dock will still show then as open once Desktop reappears, but they are no longer open?

All of this is really impressive when I have clients over (which ALL have PC's) and they just laugh at how much I spent on this crashing Apple mess.

This is what I usually get now:

panic(cpu 0 caller 0xfffffff02711160c): x86 CPU CATERR detected
Debugger message: panic
Memory ID: 0x6
OS release type: User
OS version: 19P647
macOS version: 20G314
Kernel version: Darwin Kernel Version 21.2.0: Sun Nov 28 20:41:46 PST 2021; root:xnu-8019.61.5~2/RELEASE_ARM64_T8010
Kernel UUID: CF964F28-F0BB-3F2B-9C41-E4ECB7941103
iBoot version: iBoot-7429.61.2
secure boot?: YES
x86 EFI Boot State: 0xe
x86 System State: 0x0
x86 Power State: 0x0
x86 Shutdown Cause: 0xec
x86 Previous Power Transitions: 0x20002000200
PCIeUp link state: 0x89271611
Paniclog version: 13
Kernel slide: 0x000000001f0c8000
Kernel text base: 0xfffffff0260cc000
mach_absolute_time: 0x2c04894168
Epoch Time: sec usec
Boot : 0x61e2694a 0x0003e70e
Sleep : 0x61e390d3 0x000eef36
Wake : 0x61e39f49 0x00013926
Calendar: 0x61e3a144 0x000b3ade
Zone info:
Foreign : 0xfffffff0563fc000 - 0xfffffff05640c000
Native : 0xffffffe000674000 - 0xffffffe600674000
Readonly : 0xffffffe0e6cd8000 - 0xffffffe13399c000
Metadata : 0xffffffeb00a84000 - 0xffffffeb04bdc000
Bitmaps : 0xffffffeb02284000 - 0xffffffeb024e0000
CORE 0 is the one that panicked. Check the full backtrace for details.
CORE 1: PC=0xfffffff026899b40, LR=0xfffffff026899b40, FP=0xffffffeb03f23ef0
Panicked task 0xffffffe3e6dc8628: 0 pages, 168 threads: pid 0: kernel_task
Panicked thread: 0xffffffe219f070c8, backtrace: 0xffffffeb03f13670, tid: 359
lr: 0xfffffff0268676b4 fp: 0xffffffeb03f136b0
lr: 0xfffffff026867444 fp: 0xffffffeb03f13720
lr: 0xfffffff0269a2d98 fp: 0xffffffeb03f137a0
lr: 0xfffffff0269a1f60 fp: 0xffffffeb03f13850
lr: 0xfffffff026ed15fc fp: 0xffffffeb03f13860
lr: 0xfffffff026867158 fp: 0xffffffeb03f13bf0
lr: 0xfffffff026867158 fp: 0xffffffeb03f13c50
lr: 0xfffffff0278f7488 fp: 0xffffffeb03f13c70
lr: 0xfffffff02711160c fp: 0xffffffeb03f13ca0
lr: 0xfffffff0270fe364 fp: 0xffffffeb03f13d00
lr: 0xfffffff027104818 fp: 0xffffffeb03f13d50
lr: 0xfffffff027100250 fp: 0xffffffeb03f13df0
lr: 0xfffffff0270fda48 fp: 0xffffffeb03f13e70
lr: 0xfffffff026fafbbc fp: 0xffffffeb03f13ea0
lr: 0xfffffff026e18034 fp: 0xffffffeb03f13ee0
lr: 0xfffffff026e17858 fp: 0xffffffeb03f13f20
lr: 0xfffffff026edc5a0 fp: 0x0000000000000000

 

[abad0n]

I tried this with a Thinkpad usb c external dock. It happened just as frequently. I tried a belkin dock at another point and had the same issue.

Yeah, but those docks are not DisplayLink docks. DisplayLink is important here. You need drivers etc for Dell D6000. I also tested another Dell docks and had an issue, but with DisplayLink dock issue went away.

 

[batomata]

I am having the same issue. I have iMac (Retina 5K, 27-inch, 2020) with 3,8 GHz 8-Core Intel Core i7 processor and AMD Radeon Pro 5500 XT 8 GB graphics card. When a second monitor is plugged in, random crashes occur. I have tested with different monitors, result is same. Crashes occur randomly, sometimes when I am only using a browser. I also tested it without a second monitor for a week and no crash occurred. I don't have any Adobe software installed. Also when crash occurs, iMac screen stays black while second monitor displays a green screen.

Previously I have used iMac Late 2013 and never came across a crash once. I need to use iMac for work so I can't switch to Windows unfortunately.

 

[gak1005]

I tried this with a Thinkpad usb c external dock. It happened just as frequently. I tried a belkin dock at another point and had the same issue.

I bought my Mac to an apple store in the UK and requested to speak to the store manager. I bought it in August 2020 and I just managed to get a FULL refund in January 2022. I explained all the issues I was having and how I first made them aware of the issue only days after I first purchased the Mac. I quoted my consumer rights and explained how I had given them multiple chances to fix the Mac (it had 2 logic board replacements in an attempt to fix this) but nothing worked. They offered me an exchange on a brand new Mac (same model) then I showed them this forum, plus many more on the apple developer forums and showed them that this was not just an issue with my Mac. After much deliberation, I was offered a full refund and I took immediately. I also was refunded the total cost of the apple care I purchased.

Im extremely disappointed with apple. Having to deal with their "tech support" was by far the worst experience I have ever had with apple. Constantly being told to wipe my Mac over and over and over again expecting a different result each time... it almost broke me.

I'm glad you were able to get full refund over the machine! A question - how do you get over the "wipe your Mac" phase, and actually have people to look over the machine and help you out? Is setting multiple in-person appointments with the Genius Bar the only answer?

 

[carrinli]

Yeah, but those docks are not DisplayLink docks. DisplayLink is important here. You need drivers etc for Dell D6000. I also tested another Dell docks and had an issue, but with DisplayLink dock issue went away.

Thanks for the tip about DisplayLink! I got this cheap adapter: https://smile.amazon.com/gp/product/B01CSG7TUC/
I've been using it with an external Dell monitor and haven't had ANY kernel panics in 4-5 days!! But, I've noticed that my mouse lags when I'm using the monitor with DisplayLink. It's always something... any workarounds are appreciated! I'm eventually going to take my computer in to the Apple Store again, but I'm dreading it. Has anyone else been successful in getting a refund or getting them to replace the graphics card?

 

[WeezG]

We have 2 2020 imacs. Both are i7 8-core models with 2tb SSD and 64 gb of RAM. One has the 5500 XT graphics card while the other has the 5700 XT 16gb.

The 5500 XT has been suffering from constant kernel panics. At least 1x a week but sometimes 3x in a single day. The only way to make it stop is to unplug the external monitor. We have tried multiple cables and multiple monitors, but still get kernel panic crashes.The same monitor does not cause any issue on the other imac with the 5700 xt graphics card. The 5700 xt iMac has never had a kernel panic.

These computers are used for work. Applications are pretty standard, Adobe CC, Sonos, Spotify, a font manager. Crashes can happen with an Adobe app open, just browsing Safari, or while the computer is asleep! So no correlation there.

Apple support has been pretty useless. They had us go through all the usual steps. Installed big sur. Took it in to the Apple store but it didn't crash withing the 24 hours that they held it so the had us do a complete wipe and reinstall of everything. That did nothing, it crashed again 2 days later. I found it interesting that the genius bar had zero interest in looking at our crash reports to help diagnose the problem. I guess it wasn't part of the script.

Has anyone else had a similar issue? If so, were you able to find a solution?

I realize most people don't need a second monitor, but we do graphics work and the screen real estate is essential.

I have a 27" 2020 running Monterey 12.1. I was having the same problem and it was so frustrating. At first I had an old 20" mac display, I thought that was the issue because it's probably close to 20 years old, so I got a new cheap monitor and the same thing happened. I ended up getting a 3 ft. male hdmi to male Thunderbolt 3 cord so I didn't need to use any adapters and so far *knock on wood* I haven't had any more problems.

 

[blizaine]

I know this is a 2020 iMac thread, but I don't think those are the only ones affected. I have a 27in 2019 core i9 iMac with Radeon Pro Vega 48 8GB.

I can connect two external 4k monitors (triple display including iMac), and it will work for a while. But if I jump on a video call with Teams or Zoom, it almost always KPs, so I pretty much always keep my second external display disconnected. With 1 external monitor connected, I can work without KP issues unless I let the iMac go idle. It's like when it goes idle, some background processes related to processing media in the Photos app kick in, and my iMac KPs. So I have to run a little mouse jiggle app to prevent it from going idle. If I don't have an external display connected, it idles fine. So I've connected the display to a smart power outlet, so I can easily turn it on/off or automate it. It's been this way for almost two years (when I started working from home). It's so aggravating. I've factory restored the OS, opened tickets with apple, tied different thunderbolt cables, several different docks, different monitors, even thunderbolt 4 docks, you name it.