Avaya 1692 Firmware

[oakdale]

I have a customer who purchased an Avaya 1692 conference phone. It worked fine while he loaded the new Avaya 1692
firmware into his file server directory. When it got to
the final reboot the unit froze and won't come back.

Now he can't do a firmware downgrade to see if that unfreezes the unit. Tried to local power the unit but still no go. Replaced the unit with a new one and it does
the same thing which tells me this is a firmware problem.

Any help on downgrading the firmware on this?

Thanks