Issue with MacBook Pro 2014, Thunderbolt port causes constant crash

Over the last few months I’ve been managing to live with an issue with my MacBook Pro (Retina, 15-inch, Mid 2014). It has been a real challenge to fix!

UPDATE: This issue occurred again for my MacBook Pro 2014 following an update to Mojave 10.14.6 and again for Catalina 10.15.2. I have updated the steps below accordingly.

The problem

Every so often my laptop screen would go blank, there would be 8-9 seconds where the fan would go wild and then everything would power down. I would boot the machine and have no crash report.

Sometimes it would crash once a day, other times it would be upwards of a dozen. More often, it would crash 3-4 times a day.

These issues tended to occur when the laptop was not connected to the mains. At the time of this issue starting, I had a battery condition message appear so naturally I connected the two issues.

Initial ideas

Rather than go to the Genius Bar, I tried the following:

• Boot in safe mode
• Run hardware diagnostics
• Reset NVRAM
• Reset SMC
• Audit all apps (removed where possible)
• Removed SD card
• Reviewed network devices
• Cleaned up laptop using CleanMyMac X
• Ran first aid
• Remove Chrome extensions
• Fresh OS install
• Disk Utility & Repair Disk
• OS X Recovery
• Disable/remove network properties including VPN

I did eventually get a Genius appointment and had a battery replacement which did not fix my problem but at least my battery would last a suitable length of time (assuming no crashes!)

Eventually after months of having this issue, I finally had a crash report which gave me the necessary information. Very quickly I learnt that the issue was with the thunderbolt port and has been speculated that it was introduced with an OS update.

A short term fix was to always have something plugged into the thunderbolt port (I had a spare ethernet converter) but after a few days, it did crash.

The fix

Looking for a permanent fix, I found that you could disable certain drivers. A lot of threads online suggested one driver but my laptop continued to crash (very infrequently). There was one suggestion to remove a dozen drivers but this seemed careless, I cherry picked a few and hoped for the best. Fortunately, after a week of no crashes, I felt the need to write up my findings!

The following steps were carried out:

1. Reboot with CMD+R pressed.
2. Open Terminal and run csrutil disable
3. Reboot in normal mode
4. Open Terminal
5. For Catalina only, run sudo mount -uw /
6. Run the following commands:

mkdir /System/Library/DisabledExtensions
cd /System/Library/
mv Extensions/AppleThunderboltDPAdapters.kext DisabledExtensions/AppleThunderboltDPAdapters.kext
mv Extensions/AppleThunderboltIP.kext DisabledExtensions/AppleThunderboltIP.kext
mv Extensions/AppleThunderboltPCIAdapters.kext DisabledExtensions/AppleThunderboltPCIAdapters.kext
mv Extensions/AppleThunderboltEDMService.kext DisabledExtensions/AppleThunderboltEDMService.kext
mv Extensions/AppleThunderboltNHI.kext DisabledExtensions/AppleThunderboltNHI.kext
mv Extensions/AppleThunderboltUTDM.kext DisabledExtensions/AppleThunderboltUTDM.kext

1. Reboot with CMD+R pressed
2. Open Terminal and run csrutil enable
3. Reboot in normal mode and you are done!

Ideally, I’d like to reintroduce some of these drivers and wait for the crash to come back so I know exactly what drivers to disable but I’m very happy to have a working laptop and having these drivers disabled has not changed my day to day use of my laptop.

I haven’t been able to determine what OS update caused the bug but believe the following logic boards are affected:

• 820-3662
• 820-3787

Hopefully this is useful for someone in the future!

Key reading materials

• https://outluch.wixsite.com/rmbp-crash
• https://apple.stackexchange.com/questions/290714/macbook-pro-black-screens-and-shuts-off-after-a-few-minutes-use?rq=1
• https://forums.macrumors.com/threads/macbook-pro-shuts-down-for-no-reason.2020272/page-2#post-26998901