7911 Constantly rebooting

[Gordon Ross]

We took a new 7911 out of the box and configured it up on our CUCM system (6.1.3) At first boot, it upgraded it's firmware. Once we'd configured and tested, we took the phone to site. Plugged it in, and now, it constantly reboots. All other phones at site are fine.

The displays the Cisco splash screen, then eventually, for a brief period, shows the normal screen. Then it flashes "Reboot" in the bottom left hand corner, and starts again. (It never shows "Configuring IP", etc)

We've tried doing a factory reset, and it re-images itself fine. It just never completely comes up afterwards. We've removed it from CUCM, but no change (that was more clutching at straws...)

Unless someone has a bright idea, we're planning on sending it back.

GTG

[sysjes]

Have you checked the port config? If you plug a different phone to that same port does it come up?

[Gordon Ross]

Nope. Doesn't matter where in the network I plug it in, it just constantly reboots.

[sebastiandm]

Have you checked the power levels on the switch if POe to see if it can support another POE device?

[Gordon Ross]

We've tried it on multiple switches, including my test switch, and a brand new 48 port PoE switch on which this 7911 was the only device plugged in.

I can't see power being the problem.

[sebastiandm]

Mmm,

U checked the bug toolkit then for that firmware version ?

[Gordon Ross]

I've got 10,000+ phones on that firmware fine...

[sebastiandm]

Point taken,

I would say the bootloader is probably corrupt in which case theres not much else you can do.

[paolo bevilacqua]

I never saw a really failed cisco phones (does not mean there are not), all treoubles were glitches in the dhcp/tftp process, sometime the 7911 thinks to be a 7906 and so on...

If you connect and configure tftpd323 you will see what I mean.

[Gordon Ross]

But the phone never gets as far as "Configuring IP" And when a phone says "Configuring IP" the first thing it *actually* does is CDP for it's VLAN...

[paolo bevilacqua]

You cannot be sure of what the phone actually does unless hookup wireshark to it.

Of course, if no packets emitted, it is dead for good.