Stuck at the Apple logo, looping. Recovery Mode crashing. Disk Utility unable to repair it. A failed macOS update is rarely a dead drive — it is a corrupted file system on a drive that had already started to go.
← All case files · £300 + VAT flat · Fusion £550 + VAT flat
The iMac would not get past the Apple logo. It kept trying to run automatic recovery and kept crashing. Disk Utility in Recovery Mode could not repair the disk. There was no Time Machine backup.
An update failure is almost never a coincidence. macOS upgrades rewrite a large amount of file system metadata in a short space of time — and a drive with sectors that were almost failing will sail through months of ordinary use and then choke on exactly that. The update did not break the drive. The update was simply the first thing to ask the drive for everything at once.
, which is what stopped the boot.
and SMART indicating genuine wear.
Intel iMacs with a removable drive — SATA HDD or SSD — are straightforward: £300 + VAT, flat.
Fusion Drive iMacs are two physical devices, an SSD and a hard disk, presented as one logical volume. If either half fails, the whole volume disappears — which is why a Fusion iMac so often dies at exactly this moment. Both devices have to be recovered and the logical volume reassembled from them. That is £550 + VAT, flat, and both drives must be sent.
iMacs with soldered storage — Apple Silicon, and the T2 machines — we do not attempt. The flash is soldered to the board and encrypted to the Secure Enclave. We would rather tell you that at the outset than take your money to confirm it.
The file system was rebuilt from the clone and the data came back with its original structure.
On update failures the outcome depends almost entirely on what happened between the failure and the drive arriving here. An iMac that was powered off and brought straight in is usually a clean recovery. One that spent a fortnight being rebooted, First Aid'd, and re-updated has had a failing drive read to death, and some of that is not coming back.
When a Mac will not boot after an update, the instinct is to keep trying things. Every one of those things is a risk, and they get worse in this order:
— each attempt is another full read across a surface that is already failing.
— it writes to the file system. If it cannot fix it the first time, it will not fix it the fifth.
— this is the one that ends it. A reinstall rewrites file system metadata, and on APFS that is precisely the structure a recovery would otherwise have walked back through.
Power it off. Leave it off. That is the whole of the advice, and it is free.
Drop the drive at our Quayside reception, or post it to us — it costs nothing to find out what happened. You get a written figure from the fixed bands before any work begins.