IP Phone factory reset Issues

[ASHAISAB1]

I did below procedure:

1. Start with the phone in a powered off state.
2. While holding the "#" key down on the keypad, apply power to the phone.
3. Keep the "#" key depressed until you see the LEDs on the phone begin a 'walking' sequence, where they walk down from top to bottom.
4. After you see the LED walk sequence begin, you can release the "#" key and enter one of the reset sequences below.  You have to enter the sequence as is, any deviation from the given sequence will abort the factory reset and resume a normal boot sequence.

The code for the soft factory reset is: 123456789*0#

A soft reset does the following:

1. deletes key files on the phone including /etc/init.tab
2. reboots
3. phone recovers default loads file from TFTP server

After the completion of above procedure i am getting below errors in IP Phones 

1.Error is Now "Blank Screen"

2. Another IP Phone i have done same procedure as above,that IP Phone stuck in "Upgrading"

3. "TFTP File not found Error"

4. Continues glowing both amber light sequentially and Speaker button glow then screen blank not able to reset the IP phones

[Suresh Hudda]

Do you have DHCP server (including option 150) in network to provide addresses to these phones ?

Suresh

[ASHAISAB1]

yes Suresh we have but problem with only CISCO-7940 model other models working fine...now i am confusing as its IP Phone issue or the server issue...