cisco ip phone 7942 not booting after factory reset

[askalu.weldai.ctr]

Hi,

I am encountering cisco 7942 IP phones going from registered to suddenly a blank screen and just the speaker lit is solid green. They are not responsive to any keys and don't boot up.  I have tried the factory reset, and nothing happens. Any one experience this please?

[Brandon Pierce]

You could try to blow out everything but the CNU and let the phone attempt to pull everything all over again.

Hold # as it boots and instead of 1234567890*# do 3491672850*#.  Do not do anything to the phone until it completely resets and comes back up functional.  This essentially formats the flash and only keeps the Cisco Native Unix (CNU).  If that doesn't work, its RMA time.

[Brandon Pierce]

So this worked for you then?  Just curious.

[Garima Parghi]

That worked for me!!! Thank you!!!!

[AhulaPriyankara84214]

Mr Branson

   all ready dial 3491672850*# and keep the power on more then 30 minute.but display is blank.why like this & cisco 7042g not on.

[marioguido93]

Hi,

Same problem!

With the 3491672850*# procedure, the IP phone can download firmware 8.5.2 from the TFTP server (my PC), and then try to reboot with the 8.5.2 firmware. While booting, it shuts down (after the Cisco logo). 

I tried the same procedure with another IP phone, and it can boot normally.

Why?????

Is there a way to access via console (for example) to the IP phone?

[kenet2010]

Did you get a solution to this problem? Having same issue