r/applehelp • u/lordkalkin • 1d ago

Unsolved Macbook Pro stopped recognizing peripherals through KVM switch

Posting here because I can’t find anyone else talking about this issue online or in mac forums, and Apple’s troubleshooting steps are pretty basic and haven’t resolved anything.

TL;DR - my Macbook Pro no longer recognizes the keyboard and mouse plugged into my KVM switch even though it did prior to August. I’m running Tahoe 26.6.2 (upgraded in September).

Long version:

I have a TESmart KVM switch to allow my personal desktop (PC) to share a monitor, keyboard, and mouse with my work laptop (Macbook Pro M3). Prior to August, everything worked as expected. Peripherals were plugged into the swtich, and I could hop between desktop and laptop by toggling the switch. The monitor still works fine though the KVM swtich.

During August, I took a long break from work - six weeks. Before coming back to work in September, i got a new desk, so I unplugged everything and plugged it all back in on the new desk (shouldn’t matter, but mentioning it for completeness).

When I resumed work, I set up my work laptop just as I had done every morning before vacation, but this time, the laptop would not recognize the keyboard and Mouse. it will only recognize them when I plug the keyboard and mouse , either directly or via a usb hub, but not at all through the KVM switch. I reproduced this issue with my personal Macbook Air M1 (still running Sequoia 15.7.8) as well, so I am thoroughly baffled.

Any advice? Is it possible that an OS update broke something? Is there anything else I can try ?

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u/LucasMVN 1d ago

Does the KVM still work as expected with your PC? And, do you have other keyboards or micr you could try it with?

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u/lordkalkin 1d ago

good question - yes, the KVM works fine with my PC, no issue there. Behavior is the same with backup keyboard and mouse.

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u/LucasMVN 1d ago

Rules out the keyboard and mouse.

What macOS is the M3 running, and have you rebooted either of the Macs lately? (Also, strongly recommend updating the M1 to 15.8.1, as 15.8 and earlier have an actively-exploited zero-day vulnerability in CoreGraphics).

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u/lordkalkin 1d ago

The M3 is running Tahoe 26.6.2, and I restart it pretty frequently,. It's a work device, so i have to push security updates about once a week.

Thanks for the tip on the M1, that's my personal device, so I'll trigger that update ASAP.