Phone fails to upgrade after reset to factory default CUCM 8.5

[scottsassin]

I have a CUCM 8.5.  I have a 7961 phone that fails to upgrade after a factory reset.  I have confirmed that the file term61.default.loads is in the cucm tftp server.  The phone powers up, goes to update, tries to find term61.default.loads, and resets after a bullet icon in the left hand corner of the screen.  The load version is SCCP41.9-1-1SR1S.

[Jonathan Schulenberg · Accepted solution]

Try installing 8.5(2) and then updating to 9.1(1) after that. There was a code signing key change and the burned-in image probably doesn't trust the new code signature.

http://www.cisco.com/en/US/docs/voice_ip_comm/cuipph/firmware/8_5_2/english/release/notes/7900_852SR1.html#wp164599