acmeplant wrote:
My husband and I both bought new MacBook Pros in the summer of 2020. Within a year, the 4 thunderbolt 3 ports on both machines began to fail intermittently (left side first, right side later). We were both sent new power supplies; that didn't help. We both have to reboot the SMC frequently, which helps for a limited time. Usually this has to be done in conjunction with powering down and leaving the laptop to charge overnight. Last time it didn't work for my husband and his laptop is dead in the water. Can't power on. Can't do anything. We think it's a firmware issue, since the ports still work (with dongles) for outboard gear. Apple says they've never heard anyone have this issue before. What are the odds that the only two MacBook Pros in the whole world that have this problem live in the same house? Thought I'd check here before we drive two hours to the closest Apple Store.
If this is Intel Mac— yes do both Try resetting the SMC How to reset the SMC of your Mac - Apple Support
and
Try resetting NVRAM/PRAM Reset NVRAM or PRAM on your Mac - Apple Support
(get at least two-three rounds of the chimes when holding the NRAM Reset)
You can run a user diagnostic in an effort to rule out hardware...not as definitive as Apple's own AST2 (Apple Service Toolkit) back bench diagnostic, but may kick out an error code.
Use Apple Diagnostics to test your Mac
Use Apple Diagnostics to test your Mac - Apple Support
To trouble shoot further you can:
—SafeBoot How to use safe mode on your Mac - Apple Support
Takes a bit longer to get to the login screen, does a quick disk repair before it fully boots up, and certain system caches get cleared and rebuilt, including dynamic loader cache, etc.
Login and test. Reboot as normal and test. Caches get rebuilt automatically.
In Safe mode third party system modifications and system accelerations are disabled, it removes malware, etc hampering smooth operation, however a reboot will put it back to normal mode.
This test will tell you if third party interference; extensions etc are not loaded in safe boot mode.
—Test issue in another user (or guest user) account Set up users, guests, and groups on Mac - Apple Support
This will tell you if it a universal issue or isolated to your user/admin account.
Uninstall all third party apps that are Cleaners/Optimizers/VPN/Anti-Virus
all known to cause issues on the macOS
