The MacBook Pro has three Thunderbolt (USB-C) ports plus HDMI, an SDXC card slot and a MagSafe 3 charging port, so a USB problem is often one of many devices sharing them. Apple's USB article gives the isolating steps: make sure the device is connected properly, powered if it needs to be and has any software it needs; switch its cable to another port; disconnect everything except the device, an Apple keyboard and mouse, with no hubs or extension cables; and see whether the device appears under System Information, USB. Apple lists Thunderbolt 4 (up to 40Gb/s) on M3 and M4 and Thunderbolt 5 (up to 120Gb/s) on the M4 Pro and Max, so an old cable can limit a fast drive.
Differential
Likely causes of “Apple MacBook Pro 14-inch and 16-inch USB or Thunderbolt device is not recognized”, and how to tell them apart
- 1
A cable that cannot carry data at speed
What separates it A drive mounts slowly or not at all on a cable that charges a phone
How to confirm Use a cable rated for data at the port's speed; Apple notes some USB-C cables carry data only and some charge only
- 2
A hub or dock in the chain
What separates it The device works when plugged straight into the Pro
How to confirm Apple says to connect the device directly, with hubs and extension cables disconnected
- 3
One port is at fault
What separates it A device fails in one port and works in another
How to confirm Switch ports as Apple says and note which one fails
- 4
Device software missing
What separates it The device appears in System Information but does nothing
How to confirm Apple says to install the latest software from the device maker
- 5
A damaged or dirty port or SD slot
What separates it The plug wobbles or the card is not read
How to confirm Look in with a flashlight and have a loose or bent port inspected
Before you touch a setting
Record this first — changing settings destroys the evidence
- Which MacBook Pro you have and which port or slot fails
- The device, cable and any hub or dock in the chain
- Whether the device shows under System Information, USB or Thunderbolt
- Whether the device works on another Mac
Try in this order
0 of 7 completedCheck the connection
ReversibleMake sure the device is plugged in properly, powered if it needs power and has its software installed.
Switch ports
ReversibleSwitch ports, by moving the cable to another Thunderbolt port, since Apple says to try another port first.
Go direct
ReversibleDisconnect everything but the device, an Apple keyboard and mouse. Remove hubs and extension cables.
Check System Information
ReversibleApple menu, About This Mac, System Report, USB or Thunderbolt. See whether the device is listed.
Try another cable
ReversibleUse a cable rated for the speed the device needs, since a charge-only or slow cable limits what the device can do.
Restart with power attached
ReversibleShut down, unplug, wait about a minute, plug in and start up, as Apple's article suggests.
Update software
ReversibleInstall the device maker's latest software and any macOS update, since old drivers are a common reason accessories stop working.
Model-specific
What is true of this model and not of its siblings
- Ports by model
- M3 and M4: three Thunderbolt 4 ports. M4 Pro and Max: three Thunderbolt 5 ports. All: HDMI, SDXC slot, MagSafe 3 and a 3.5 mm headphone jack, per Apple's tech specs.
- Speed
- Thunderbolt 4 up to 40Gb/s; Thunderbolt 5 up to 120Gb/s, per Apple's tech specs.
- Part numbers
- No part number is involved for the Mac. Cables and hubs are identified by their own makers' model numbers.
- Repair cost
- Apple quotes port repairs after diagnosis. iFixit's table lists Apple's US estimate for a MacBook Pro battery at $249, the only published fee for these Macs.
- Other models this page answers
- These steps also fit the MacBook Pro 16-inch (M4 family), MacBook Pro 14-inch (M3 family).
Stop boundary
When this stops being a self-service repair
- !If a device fails in every port and works on another Mac, contact Apple or an Authorized Service Provider
- !If a port or the SD slot is loose, bent or corroded, book a repair
- !If only one hub or dock fails, contact its maker
Evidence ledger
Sources behind this answer
Connection, another port, disconnecting hubs, System Report and device documentation.
Connecting to a port directly rather than a hub or dock.
USB-C ports and charging, one port at a time.
72.4-watt-hour battery, three Thunderbolt 4 ports, 24 hours video, Center Stage camera and display support.
Three Thunderbolt 5 ports, 72.4-watt-hour battery and up to four external displays.
100-watt-hour battery, 140W adapter, Thunderbolt 5, HDMI, SDXC and ProMotion.
Apple silicon MacBook Pro history: 14-inch and 16-inch generations, ports, displays and fans.
Exact questions
Common questions
Can HDMI and Thunderbolt displays run together?+
Yes. Apple lists combinations such as two 6K displays over Thunderbolt or one over Thunderbolt and one 4K display at up to 144Hz over HDMI on the M3 and M4.
How many ports does the Pro have?+
Apple lists three Thunderbolt (USB-C) ports, an HDMI port, an SDXC card slot, a MagSafe 3 port and a 3.5 mm headphone jack on the 14-inch and 16-inch M3 and M4 Pros.
Why is my SD card not read?+
Check the card is fully inserted and reads on another device. Apple lists an SDXC slot; a damaged card or slot is the likelier cause than macOS.
Can I charge and use displays at once?+
Yes. The Pro charges over MagSafe 3 or a Thunderbolt port while displays use the others; Apple says only one port charges at a time.
Does HDMI carry USB devices?+
No. HDMI is a video and audio output; USB devices need a Thunderbolt (USB-C) port.