The 7906G I have does not boot. It has a blank screen and the Settings light is lit up green. It does not respond to holding the # key while powering on the device.
The other 7906 I have boots and the SCCP firmware upgraded fine. Both phones are connected to the same switch and same CCME 4.3. CCME, DHCP, TFTP and Option 150 are all set. All my other phones work aside from this one. This process is what made the phone unresponsive.
1. Hold down the # key on the phone.
2. Continue holding down the # key and re-apply power.
3.While still holding the # key wait for the Message Waiting Indicator (MWI) light on the handset to start flashing.
4. Once the MWI light is flashing, release the # key and enter the following sequence exactly on the keypad: 3491672850*#
You might want to try few things which require some time and patience.
My 2 cents ...when phone reset to facoty default it went back to original load/firmware which it came with originally.
And your CCME might not have that flash load/firmware.
So you might wanna use wireshark and sniff traffic from back of the phone to see what firmware file its trying to load.
Then put that firmware on router.
Try to reregister that phone ..and give it some time (2-3 hours) trust me it happened with me ...best would be to leave it overnight ...and see if it works