What should I do if my Mac won't recognize USB devices?

John Galt wrote:

If that Mac's ports can't be used then Target Disk Mode will not be an option since you will be unable to get past Step 1.

Transfer files between two Mac computers using target disk mode - Apple Support

Target Disk Mode may not be an option, anyway.

Apple added a requirement that if either Mac is running Big Sur or later, the connection must be a Thunderbolt one. All new Macs run something more recent than Big Sur, and all 2009 Macs predate Thunderbolt, making it impossible (at least officially) to use a 2009 Mac as a Target Disk for an Apple Silicon one.

It is supposed to be possible to use an Apple Silicon Mac as an external USB drive for another Mac, but in this case, there are a couple of potential obstacles:

• The OP's USB ports aren't working
• Even if they were, an Apple Silicon Mac would have an APFS-formatted SSD. Unless that old Mac is running High Sierra, it won't be able to make heads or tails out of an APFS-formatted disk. It might offer to format the new Mac's drive – an offer that the OP would do well to refuse!

Try a different external drive. If one that you can verify as working won't mount, then absent a working Internet connection you probably will need to either try Target Disk Mode with another Mac:

Transfer files between two Mac computers using target disk mode - Apple Support

or to remove the hard drive and connect it to another computer, either one you can borrow or the new Mac when you get it, to get access to your files.

Regards.

The usual way is to create a Time Machine backup, built into every Mac for about the past two decades.

Back up your files with Time Machine on Mac - Apple Support

If that Mac's ports can't be used then Target Disk Mode will not be an option since you will be unable to get past Step 1.

Transfer files between two Mac computers using target disk mode - Apple Support

If your FireWire port still works, you might be able to attach a FireWire / USB drive. You would use FireWire to hook up this drive to the dying Mac, and USB to hook it up to a replacement one.

I say "might" because if the old Mac is dying, who knows if the FireWire ports still work – or if the internal drive still works well enough to allow any backup operation to succeed?

As far as I know, there is only one vendor that still makes FireWire drives – and only in desktop versions. They used to have portable bus-powered ones, but those seem to have been discontinued.

Other World Computing – OWC Mercury Elite Pro (USB 3.2 (5Gb/s) + eSATA + FireWire 800)

By the way, please get into the habit of making backups of your new computer.

It sounds like you did not do that with the 2009 Mac – so now, saving your photos may be "touch and go". On any current Mac, if the computer dies, there is basically no chance of saving any data on the internal SSD. Most Apple Silicon Macs have their SSDs soldered in, and all Apple Silicon Macs encrypt the contents of those SSDs with keys that are held within the Apple Silicon processor.

You must back up your new Mac before catastrophe happens if you want any realistic chance of getting anything back.

I know...

Inoperable ports will complicate recovery, at best.