A firmware update in OneSync never finishes — is my device dead?
A firmware update that looks stuck is usually recoverable. Never unplug, wait 30 minutes, then power cycle and relaunch from the latest OneSync.
Before anything
Almost certainly not. Never unplug the device during an active update, and give the update at least 30 minutes before you intervene.
Recovery steps
Confirm you are running the latest OneSync version from hexoskin.com, since older versions contain update bugs. Close OneSync completely, power cycle the device, reconnect it by USB directly to the computer (no hub), then relaunch OneSync and restart the update.
If the device no longer boots, stop retrying and contact support with the device serial number and your OneSync version. A recovery procedure exists and the device is usually not lost.