A long time ago I was feeling rich, so I spent nearly $2000 on one of the first-generation Mac Airs. This led to me travelling with a laptop I could afford to lose instead. I loved the Air for all sorts of reasons but one of its important tasks was to back up my iPhone every day. And, of course, being something of an expert on preserving digital information, then back up the Air to an external USB hard disk using Time Machine. Lots Of Copies Keep Stuff Safe.
In the end I had to upgrade to a more recent M1 Air, not because the old one stopped working, but simply because the USB ports stoppped working, so it could no longer backup the iPhone or update the Time Machine disk. The new Air was impressively fast and had two USB-C ports, which it used both for data and for power. I continued to back up the iPhone and the Air daily
Fast forward to last month. The new Air's USB-C ports had been a bit flaky for a while, but now one failed. It wouldn't transfer data or power. A few days later the other port stopped transferring power, leaving me with no way to charge it. It was about 85% charged, so I powered it off.
I thought "I'm OK, I have yesterday's Time Machine so I can get a new M2 Air and initialize it from the disk". So I ordered a new one and, as soon as it was delivered, plugged in the Time Machine disk and fired up the Migration Assistant. It asked me what disk it should use. I wasn't able to select the Time Machine disk because, to my surprise, the Air couldn't see it. Plugging the disk into my Linux desktop revealed that in the couple of weeks since the day before the M1 Air failed, the Time Machine disk had died.
At this point I remembered that when I powered it off, the M1 Air still had a USB-C port that transferred data, even if it didn't work for power. There were two ways to initialize the M2 Air using the remaining battery, either create a new Time Machine disk using the one USB-C port that transferred data, or via Bluetooth. I found a USB-C external SSD, which I figured would use less power, powered up the M1 Air, plugged in the drive, started a Time Machine backup, and crossed my fingers.
After a long, agonizing wait the backup finished with still quite a lot of battery left, so I powered off the M1 Air and used the disk to initialize the M2 Air. Apple's Migration Assistant worked flawlessly, and I relaxed. The best thing about the M2 Air is that Apple went back to powering it with MagSafe! Their fragile USB hardware could no longer prevent the machine charging.
So the lesson was that I needed to have two Time Machine disks and use them alternately, so even if the most recent one failed I would have a backup only one day older.
The next problem came when I plugged my iPhone into the M2 Air to back it up. I got "unknown error 7014". Google had no trace of "unknown error 7014" so, baffled, I made an appointment with the "Genius" at Apple's Palo Alto store. In the faint hope that the M1 Air could be fixed, I took both Airs and the iPhone with me.
The Genius was very good. He rapidly figured out that:
- "unknown error 7014" was caused by the fact that, despite its having been delivered a few days earlier, the M2 Air's operating system was out-of-date. A software update overnight fixed the problem.
- He confirmed that the M1 Air's USB-C ports had failed and, to my surprise, explained that the ports were on a daughter-board that could be replaced. It was a $15 part and $90 in labor, and completed overnight.