Can I downgrade firmware on a 7912

[shahedvoicerite]

Hi,

I have the latest signed load on a 7912.

Can I downgrade it ?

I did manage to do it accidently, by pressing some key combinations on the phone, which cause the phone LCD to blank out, but would rather do it the prescribed way.

I have read that its not possible to downgrade from a signed load, but since I did manage to do it accidently, I am sure its possible.

[Brandon Buffin]

You can downgrade the firmware, just not to an unsigned load. You can downgrade the firmware on a single phone by populating the Phone Load Name field in phone configuration or you can downgrade all phones of a given type by changing the Load Information field for that phone type in Device Defaults.

Hope this helps. If so, please rate the post.

Brandon

[shahedvoicerite]

Yes, I am aware that you can downgrade from signed to signed.

I however managed to completely wipe out a 7912, and get it to a state where the LCD blanked out, and the hold and config lights where steady red/green.

The phone had a signed firmware earlier.

Its probably because I interrupted a firmware load by pressing some key combination, but am not sure exactly what I pressed :-(

One thing that did happen, was the phone started ringing at one point, flashed a message saying "Upgrade sucesful" and then got into this "locked" state.

Perhaps I hit upon some unsupported "feature" (?)

I was then able to load an unsigned firmware onto it.

I had to however rename the unsigned firmware file from CP 7912xxxSCCPXXX.zup to cp7912r.zup in order for the phone to download it via tftp.

Thanks

Shahed.

[mohammedmahmoud]

Hi Shahed,

Please allow me to interrupt you here, i got a question.

After upgrading my Cisco 7912 IP Phones, arround 5 IP Phones get to a state where the LCD blanked out, and the hold and config lights where steady red/green. Are the Phones dead ? What happened and what is the solution ???

Please your fast reply is appreiciated.

Thanks in advance.

[a.gooding]

Did you ever fix this issue. i am having the same issue where my 7912 are "dead". if you did, could you advise on what was done?

thanks