A first...

I have two machines - my work machine, the M2 Pro, and my old 2018 Intel mini which now runs Boinc, my weather station and Plex.

Did the most recent OS update, to 13.5.1 on the M2 Pro a couple of days ago with zero issues.

Did it today, via screen sharing did the Intel mini.

All seemed fine at first, until I noticed that shares weren't mounting on the M2 Pro. In fact it turned out that the mini could not detect any USB-C devices (neither of its ext HDs nor, when I tried, my USB-C monitor) - couldn't even see them, never mind mount.

Did all the usual tests - the drives mounted fine on the M2.

Restarted/ shut down and restarted/ swapped cables about/ dug out my old screen and keyboard and did an OS reinstall (very easy these days). No joy.

You know that thing that internet experts and Apple (sometimes) tell you to try, the thing you do just so you can say "I've done all the usual troubleshooting" in order to make the support call a little less tedious, knowing that it will achieve nothing?

Well, folks: resetting the SMC actually worked. Completely.

I have never know this, or any of its various forebears, to make a blind bit of difference.

I feel I should mark the occasion somehow, but can't think how.

In reply to a post by ian_c:

Well, folks: resetting the SMC actually worked. Completely.

I have never know this, or any of its various forebears, to make a blind bit of difference.

It worked for me once, but I can't remember what the issue was- it was a couple of Macs and quite a few OS's ago!

But yes, I'm sure it's usually done because it's quick and easy rather than in any expectation of it doing anything useful

Same here. It’s just the same as the BIOS settings getting corrupted on a PC. Rare, but it does happen.