[cisco-voip] 7906 phones stopped working with CME

[Erick Bergquist]

Hi,

I have a strange issue, have about 15 7906 model phones on a CME 4.1
system and all of sudden all the 7906 phones except 1 no longer
function correctly. They worked fine before. They just keep cycling
trying to do something, if we put a 7911 model phone on same cable,
same switch port, etc it works fine. We've rebooted the CME router
also even and the phone is getting a DHCP address from the DHCP server
and I can ping it briefly as it cycles.

On the phone itself, you power it on, the lights blink, then after a
couple seconds the Cisco logo is displayed on the LCD and in corner
there is square with a checkmark in it on first cycle after a power
on.
On subsequent cycles the phone does, it displays logo with a circle in
corner with a diamond or square in the circle (can't really make it
out).

What is the factory reset procedure for the 7906?
I tried powering it on with holding down # key and then releasing when
it lights up, then entering the 123456789*#0 sequence but that did not
make any difference and I let it sit for 15 minutes after doing that.