If it's a hard reset (i.e., complete power down and reboot) then I'd look at the physical layer first. Check errors on the switchport the phone is connected to and, regardless of errors seen/not seen, at least swap cables or put the phone in a different physical location and see if you have the same issue.
My assumption is this is a single phone...not just any old phone resetting whenever it wants.
Are you getting this error “Installer User Interface Mode Not Supported. The installer cannot run in this UI mode. To specify the interface mode, use the -i command-line option, followed by the UI mode identifier. The value UI mode identifiers...
The below trick might come handy when you have to add a new node to a cluster but you don't have or is unsure of the security password for the publisher. This procedure has been around for ages.
1) Login into the CLI of the Publisher.