MP 7,1 USB Hub Preventing Startup?

[Grumply]

Hi guys,

Run into a weird one recently. I've been having a bunch of intermittent startup issues, which have generally required an SMC reset (pull the power plug out for 20 seconds) in order to get past.

But I decided to be stubborn this evening and try each cable plugged into my 7,1 one-by-one to see if any peripherals might be the culprit.

When I got to the USB-A cable that connects the USB Hub built-into my monitor, the system started up instantly. I plugged it back in (before startup completed) and the startup then failed.

Removing it for the full startup, allowed the system to boot just fine, and then plugging it back in (once I was into OSX Big Sur) it's working normally.

Has anyone run into something like this before? Could it be a dodgy cable causing the problem? Or a dodgy port on the monitor?

 

[cobra521]

Grump,

Trying another USB cable would seem to be the simplest trouble shooting step.

I recently had a USB cable go bad on a videocamera remote, and bought one with the correct end fittings. It gave me one of those "educational" moments: it was the wrong kind! I think I got an OTG cable (don't ask me what that means - I don't know) and it didn't work; same symptom as the cable that went bad - the remote did not function. For a while I thought I'd bought a bad cable until the manufacturer of the remote sent me a new cable which worked immediately.

Message: there seem to be at least two different kinds of USB cables, not compatible with each other.

News to me...

Tom

 

[Grumply]

Grump,

Trying another USB cable would seem to be the simplest trouble shooting step.

I recently had a USB cable go bad on a videocamera remote, and bought one with the correct end fittings. It gave me one of those "educational" moments: it was the wrong kind! I think I got an OTG cable (don't ask me what that means - I don't know) and it didn't work; same symptom as the cable that went bad - the remote did not function. For a while I thought I'd bought a bad cable until the manufacturer of the remote sent me a new cable which worked immediately.

Message: there seem to be at least two different kinds of USB cables, not compatible with each other.

News to me...

Tom

I've switched it out the problematic USB-A to USB-B cable for a USB-C to USB-B, which sort-of works. But it requires me to physically turn the monitor off at it's power switch (on the back) rather than the standby button (which is convenient and up-front), before the cable will actually become active (allowing me to use the mouse I have plugged into its USB Hub.

It's all pretty messy and frustrating, especially since it was all working fine until I "upgraded" to Big Sur.