Question

Hello,

I am having a USB problem with my Presonus Itwo. The USB power cuts out on everything attached to USB intermittently. It comes back on immediately but causes pops and clicks in the audio. I have removed every device one by one besides the iTwo and the problem still occurs. I have hooked everything back up one by one except the itwo and everything works fine. I have tried different cables and different ports, and a powered USB hub.. I have upgraded firmware and drivers. I only noticed the problem after upgrading to Sierra but I wasn't doing a whole lot of recording before that so I am not sure about when it started. I can run with the built in audio with no problem.

I use Logic X but the problem occurs while running no programs running at all.

Any help would be appreciated.

Imac 21.5

2.7GHzIntel core I5

8G RAM

Answer 1

You mention that this started when you moved to Sierra should be a good indicator for you right there. 

You have some options to consider, try in this order. 

A) Re-install Combo Update for your Mac OS version. 

1. Click on the Apple in the upper left corner of your screen and click "About This Mac"
2. The next screen will show you which version of OS X you have installed. (ie 10.12.1, or 10.12.2, etc) 
3. Go to your web browser and do a search for that version of OS X with the words "combo update" (ie Mac OS X 10.12.2 Combo Update)
4. Go to the Apple.com link for the combo update and download it. 
5. Make sure to unplug all devices from your system before you run it. This will allow all preferences to get reset correctly. 
6. Once done, you're system will be properly refreshed to the OS version install. 

B) Take your iMac to the Apple Store Genius bar to have them check to see if you have a Corrupt OS Install

• We have seen on several occasions where customers elusive strange OS behaviors were the result of a corrupt OS, which the Apple Genius bar was able to solve. 

C) Contact Support. 

• If that does not work, then there may be something wrong with your interface, contact support through your http://my.presonus.com account so a support agent can help investigate further and/or determine if an RA is necessary to repair your unit.