![mac powerbook pro usb ports intermittent mac powerbook pro usb ports intermittent](https://cdn2.macpaw.com/images%2Fcontent%2Fhow-to-new%2FWhat+to+do+if+your+Mac+USB+ports+are+not+working+F+1200x630.jpg)
I do audio production meaning I sometimes use a LOT of USB devices, including eLicensers, an audio interface, synthesisers etc. Interestingly, the USB 2 hub is unpowered. I don't know why this behaviour occurs, but keeping 'like with like' has worked in my situation. In particular the problem seemed to be arising when having USB 2 devices attached to any hub on the USB 3 port (regardless of whether the hub was USB 2 or USB 3). It seems when doing this everything stays connected and stable. I attached the USB 3 hub to the USB 3 port (on the right) and attached only USB 3 devices to that hub. Repeat the same operation for port farthest from the front.Īfter trying every possible combination of hubs and configurations I could try, and with the very helpful guidance of daniel Azuelos (other answer) it turns out that in my scenario, everything started working seemlessly when I attached a USB 2 hub to the USB 2 port in my Macbook Pro (on the left), and attached only USB 2 devices to that hub. Note on which bus is this external USB port. to refresh the USB connection information. To check this hidden cabling, just use your external mouse.Ĭonnect it on port nearest from the front. This value might be different depending on the USB port available outside and what is already connected on it internally.Īs a basic simple rule, avoid the external USB port which is on the bus where is connected the FaceTime HD camera ( Current Required (mA) = 500 mA).įor example, on a MacBook Pro, I discovered through trials that my FaceTime HD camera is on the bus with the USB external port nearest from the front. Verify that the sum of the Current Required (mA) of all the equipmentsĬonnected to the same internal USB hub don't exceed the Current Available (mA) for the hub. Include this screen capture within your OQ (original question). Make a screen capture: command shift 4, space, select the USB map window and click.
#Mac powerbook pro usb ports intermittent mac#
Lower part of the window to have a complete vue of all your USB equipments. These Mac models have Thunderbolt / USB 4 ports: iMac (24-inch, M1, 2021) MacBook Pro (13-inch, M1, 2020) MacBook Air (M1, 2020) Mac mini (M1, 2020) You can connect a single external display and other devices that connect using either a Thunderbolt 3 cable or USB-C cable. Select the USB bus where is connected your USB hub, and enlarge the
![mac powerbook pro usb ports intermittent mac powerbook pro usb ports intermittent](https://blog.pcrisk.com/images/stories/blog/2018/mac-usb-ports-not-working-how-to-fix/reset-smc.jpg)
Open the > About This Mac > System Report., Just wondering if there are any suggestions or recommendations as to how I can troubleshoot or resolve this?įollowing are screenshots of the USB map (two separate screenshots as the contents of the USB 3.0 Bus details page didn't fit in one screen)ĭisclaimer: this is an answer under construction. It's very frustrating and inefficient for my workflow. To reconnect them, bizarrely, i seem to need to unplug and replug each device in 3 times specifically. But they also sometimes disconnect without this trigger. This USB hub is connected to its power adaptor.įrom memory this problem also existed before El Capitan update.įor work I use Microsoft Lync for Mac, and I sometimes notice than when a new instant message arrives, my keyboard, mouse and headset will disconnect. I bought this one in the hope it might resolve this problem, but it didn't. I'm currently using a Targus 7 port USB 3 hub ( ) but this problem existed when I was using an older USB hub.
#Mac powerbook pro usb ports intermittent trial#
I even bought a USB voltmeter/ammeter to check the available power! So I don't think it's a power issue.Ĭould a malfunctioning USB device interrupt connections to both of my MacBook's ports? (And is there anyway I could diagnose the culprit other than trial and error?) Or is this a fault with my MacBook Air?
![mac powerbook pro usb ports intermittent mac powerbook pro usb ports intermittent](https://iboysoft.com/images/summary/usb-ports-not-working-on-mac.jpg)
But the hard drives are mains powered, and I have mains powered USB hubs for most other devices. Some devices (such as the audio interface) are bus powered. This causes the hard drives connected to my right USB port to disconnect, and the audio interface connected to my left USB port to lose sync (and therefore sound horrible!) Occasionally, USB appears to stops working for an instant on my MacBook Air.