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7942 not registering


My 7942 IP phone is not registering in my UC500. when i connect it starts with a screen saying 'upgrading' and then it shows 'term42.default' upgrading and finally the screen becomes still with a black dot. I am not able to use any keys in the phone. even i am not able to factory reset the phone. the rest of the phones which i connect along with this is working fine. kindly help me in this issue.

Hall of Fame Master

Re: 7942 not registering

You need to load firmware files and configure correctly for the update to complete, if you search the forum, there are many cases like your.


Re: 7942 not registering

Hi Paulo,

i am a beginer in this field. so kindly help me.

the phone 7942 shows 'term42.default'  upgrading  0%.   I have loaded the the firmware to the UC 500, but still the phone doesnt seems to work.

Also how come only one particular phone doesnt work when all other 7942 worked.

it would be very much helpful if i  could know how i can proceed with.


Re: 7942 not registering

Hi Shabeer

Please check the firmware. Secondly please check whether the phone is supplied with cisco recommended power. Remove any other phone which is registered and working fine and connect your 7942 to its ethernet cable. I am not sure about this. But you can try doing all this steps. All the best.


Re: 7942 not registering

hi khan fawaz.

its running on recommended power. regarding firmware , how can i know this particular 7942 needs which firmware version?

Cisco Employee

Re: 7942 not registering

If you factory reset your phone, it will need to have access to a TFTP server (that it locates via option 150 from the DHCP) to download it's image again. So make sure you have firmware 8.5(2) loaded on your TFTP as the default firmware. More recent firmware may be rejected by the phone as the signing keys have changed after that version. That load has both the old and the new keys so once you installed that you can go to any version you want.

If that is not working as well, grab a sniffer trace so you can see what the phone is requesting.


Re: 7942 not registering

hi bvanturn ,

thanks for ur comments.

I have done exactly what you asked for. but still it doesnt work.

Using CCA, i have done a debug log. the output for the debug is attached.

also it would be helpful if you could say how to do a sniffer trace, since i dnt know how to do it.

right now in the topology view in CCA, i can see this device having an IP, but the phone screen appears the same..