Advice on how to investigate iMac crash?

[BShanks]

Hello,

My 2017 iMac is running off an external T5 SSD running Mojave. Generally runs great but I’ve twice experienced a similar issue over the past few months and am hoping for advice on the best way to diagnose. I am very new to MacOS and am unfamiliar with crash reports.

Basically, twice, after waking up in the morning, I’ve noticed that the LED light on the T5 external SSD drive has been flashing very rapidly. When I move the mouse to wake the computer up the screen is black and the only thing I can do is restart the computer by pressing and holding the power button.

The first time it happened I thought it might have to do with sleep settings so I disabled power nap, etc and then everything went back to normal, but now it happened again.

I do use a VPN app, and have several other little applications running (i.e the ones displayed in the menu bar at the top right of the screen like Dropbox, Box, Turbo Boost Switcher, etc) so it may be due to one of these.

It there a report that I can run after turning on the computer (it is still off after I shut it down) to see what happened?

Thanks so much!

 

[nambuccaheadsau]

The report is found in Applications > Utilities > Console > Crash Reports.

 

[xgman]

outside of a possible crash report, you probably would need to start process of elimination by turning startup stuff off and trial and error. It's a tedious process. I would turn off anything that you don't absolutely have to run at startup and see how things go. I would definetly turn off stuff like turbo boost switcher and any file encryption for starters. Do a simple "repair/first aid" of the SSD in disk utility to see if there are any problems. While the computer is running normally, you can open up "activty Monitor" app in the Utilities folder and sort by cpu, or memory, or disk and see if there is any weird stuff going on. So many things could be at play here. Key is to simplify.

 

[BShanks]

Thanks for the responses! Just to confirm:

1. Is what I experienced a "kernel panic" (unresponsive computer with LED on external drive blinking rapidly)?

2. I followed the advice to see what was listed under the console, and under "User Reports" there was an entry referencing my VPN application and a crash occurring last night. I guess that was it. It also listed an earlier crash that occurred about a month ago for "Advanced Blocking" but referencing AdGuard for Safari in the details. Perhaps that was the earlier one I experienced.

 

[jerwin]

From the T5 manual

Understanding the LEDs
The following table describes T5 Status LED behavior.

Status	LED Behavior
Plugged in / Idle	Solid blue
Read / Write	Blinking blue
Safely Remove / Computer Sleep Mode	Blinking red 1 time