Cisco IP Phone: Blank screen of death
If you get blank screen "of death" at your Cisco IP Phone after power on - you need make next manipulations:
- Set up DHCP, TFTP (you must already find procedure of firmware download, here for example);
- IS IMPORTANT!!! Make phone connected to Cisco switch with enabled CDP on port;
- Power on phone. If phone is alive - it start procedure of firmware download. Wait about five minutes.
If nothing happen few minutes after phone was powered on.
- Power off phone;
- Power on with pushed # button;
- When buttons blink - release button and type code 3491672850*# - it make hard reset, format flash, erase all settings
- If phone is alive - it must start procedure of firmware download. If after all you get blank screen of death - I think phone is totally dead.
After all nothing help. Make phone connected direct to computer. Start sniffer software (such as WireShark) and try to analyze captured packets from phone. If no traffic captured from device then it mean device is totally dead.