Hi, we have a problem with our SPA502G handsets.  Our previous comms admin has left the company, taking the admin password with him.  We have no way of contacting him to retrieve this.  We are now stuck with 10 handsets that are unable to be factory reset in order to move to a new (SIP) provider.  The handsets are out of warranty, so we have been happy to open them up in the hope that there may be a backup battery that could be removed, clearing all settings and allowing the handsets to be "hard" reset.  This does not appear to be the case.

There are a series of jumpers, including 5 pins with a group name of "J3"

Do any of the experts on the forum know of a hardware reset, perhaps using the PCB jumpers to reset the phones to factory settings so that we can reuse these handsets?