Can't Mount CD and Flash drives

[wellardmac]

I have a problem that I don't know when it even started. The symptom is that I can no longer mount flash drives or CDs onto my desktop MacPro running Sonoma. I don't know when it started, as it's not something I do often. Certainly started within the last month or so after recent software updates, as I remember uploading a couple of new CDs to music sometime in the Fall.

This is doesn't appear to be consistent with the mounting problems I've seen others post about, as my external drives, phones and iPads are mounting without issues, this seems limited to flash drives and CDs.

I checked and the drives are not showing up in the drive utility. I did the usual PRAM and SMC resets. Those didn't work. I even went down to a bare reformatted drive and started over - rebuilt from Catalina to Ventura and back to Sonoma and nothing seems to be addressing the issue.

Any ideas on what I'm missing?

 

[Bigwaff]

What year and model Mac Pro? Internal or external optical media drive?

 

[wellardmac]

2019 MacPro. External Optical drive (An LG that has worked fine before)

 

[Bigwaff]

I checked and the drives are not showing up in the drive utility.

Do the flash drives and the external optical drive appear in System Report under a USB bus in the USB Device Tree?

 

[wellardmac]

Do the flash drives and the external optical drive appear in System Report under a USB bus in the USB Device Tree?

No - even though the USB drive is getting power and the LED lighting up.

Same deal with the optical drive. it's getting power and spinning the disc, but not showing up anywhere.

 

[Bigwaff]

Sounds like your IO card is the problem. Have you tried USB-C adapters with the devices?

 

[wellardmac]

Sounds like your IO card is the problem. Have you tried USB-C adapters with the devices?

I bought a USC-C optical drive to see if that fixed the problem and it did not (tried it in multiple ports before returning it).

 

[wellardmac]

I found it. This is a dumb one, but I'll own it. With the machine only having one USB port (thanks Apple!) I didn't check what happened if I connected a USB device directly to the USB port on the back of the machine (that is a pain to access), as I had it going through a splitter on the USB port on the monitor. Turns out that the issue is somewhere along the path from the monitor USB to the desktop.