On your switch interface to your router, add these commands as well for testing:
switchport trunk encapsulation dot1q
switchport trunk allowed vlan 10,20
Then, double check that you CUCM TFTP is actually up and running and that you can retrieve a file. One way to do that is from your router, type this command
more tftp://10.1.1.100/term62.default.loads
You should see the contents of that file in your terminal window. If not, then there's a problem with your TFTP on CUCM. Try activating, or restarting the service. If that still doesn't work, SSH into CUCM and validate that the file even exists with the following command
file list tftp /term62.default.loads
It should not say "no such file or directory" but instead say 1 file found and list the filename.
Keep in mind that when you factory reset the phone, it has to have DHCP with Option 150 so it can request the file term62.default.loads, which itself has a list of files in it, all of which need to be accesible via TFTP as well. So, when you do your "more" command on the router, look at the bottom of the output and you'll see these files (your versions could be slightly different than mine)
jar42sip.9-3-1ES26.sbn
cnu42.9-3-1ES26.sbn
apps42.9-3-1ES26.sbn
dsp42.9-3-1ES26.sbn
cvm42sip.9-3-1ES26.sbn
So, go back the SSH into CUCM and run the "file list" command five more times to make sure those files are also there. You can try a "more" command on each of those if you want, but be warned that these are not text files and they are large, so outputting their contents into the terminal would not be ideal.
Last but not least, if you validating everything, then you need to try the other factory reset option. It takes much longer, and has little status display on the screen, so it's best to start the process and then leave it alone for like 1 to 2 hours before you do anything. In fact, just do it before bed, and then when you wake up it will be done.
The key sequence for this other factory reset option is as follows:
3491672850*#
Good luck.
Ok cool, the phone is PID VID: CP7962G V15
The phone was running on CUCM 9.1.2, but i am now using 8.6.2
I don't know if it makes a difference, downgrading the firmware
looking at this I'd say this is your problem. Its likely you upgraded the firmware on that phone when it was on a later version of CUCM and are now trying to downgrade it. Go and download the latest version of firmware and upload it to your CUCM (whichever the latest version you can find is). I've seen multiple times where phones do not downgrade properly and have fixed it by upgrading the actual firmware for some reason going down hasnt worked for me short of opening TAC case.