MacBook Pro random shutdown

[severn]

My MacBook Pro is 2014 version. It's still running well, except since early this year, it started to randomly shut down, after freezing for about 10 seconds.

It can happens a few times within an hour. It happens more often when the MacBook is running on battery. The battery is still healthy.
I usually got a shutdown code of "-128", and couldn't find other crash reports.

I did the following, but didn't help much:
- do a clean reinstall of OS (Big Sur)
- reset SMC / NVRAM
- created a new user
- remove most applications

I run the apple diagnostic test and didn't find any problems.

Any suggestions are welcome. Is this more related to hardware problems?

 

[Mr_SMT]

I had a similar problem with my 2019 16“ MBP. It was randomly crashing since I bought it and diagnostics showed no failures. I finally took it to Apple Store last week before my Apple care+ expired, it turned out to be a RAM issue and they shipped it for repair.