Restoring a 75 GB iTunes backup takes hours — and the worst moment to see it fail is at the very end, when iTunes suddenly reports that “the iPhone was disconnected.” The good news is that other users have hit exactly this wall and found ways through it. Here are the reader-tested workarounds that get a long restore across the finish line.
What actually goes wrong
The restore runs for hours and appears to progress normally — then dies right at the end with the “iPhone was disconnected” message. One reader’s theory explains why: during a very long restore, the iPhone sits at 100% charge for an extended period, and the device’s power management briefly stops charging. That momentary change can break the iTunes session and abort the restore. Whether or not that theory is the full story, the workarounds built on it genuinely work.
Reader-tested fixes that complete the restore
- Restore on an earlier iOS version. One reader confirmed that downgrading to iOS 9.3.5 and restoring the very same backup there completed without a hitch. Treat this as a community-tested workaround rather than official guidance — it is what worked for a real user with the exact same error.
- Drain the battery before restoring. Alternatively, run the iPhone battery down to about 5% first. With the phone actively charging throughout the whole restore, the power-management pause never kicks in and the session survives to the end. MacRumors forum threads echo this trick for long iTunes restores.
- Use the right hardware. Restore with a genuine Apple cable plugged directly into a rear USB port on the computer — not a hub. A flaky cable or port is the most common reason a connection drops mid-restore.
- Prepare the computer. Update to the latest iTunes, and disable the PC’s sleep and screen-lock so nothing interrupts the hours-long transfer. Apple Support documents the full official restore-from-backup procedure you should follow alongside these workarounds.
If it still doesn’t work
Start over with the battery-drained method combined with a genuine cable and a rear USB port — that combination has the best track record. If your iPhone keeps dropping its charge during syncs, read our guide on iPhone stops charging from computer after an hour, and if you want to avoid version-related restore pain entirely, see how to completely block iOS 26 updates on iPhone.
FAQ
Why does iTunes disconnect the iPhone at the end of a long restore?
The likely trigger is power management: after hours at 100% charge, the iPhone briefly stops charging, which can interrupt the iTunes session. Cable, port, iTunes version and PC sleep are the other usual suspects.
Should I try the battery-drain trick or downgrade first?
Try draining the battery to about 5% first — it is quick, harmless and confirmed to work. Downgrading the iOS version is the heavier fallback for when nothing else completes the restore.
Wrapping up
A restore that fails with “iPhone was disconnected” after hours is infuriating, but it is not the end of your backup. Restore on iOS 9.3.5, or drain the battery to around 5% first, keep a genuine cable and a rear USB port in the mix, and your 75 GB of data will land on the new phone intact.
