Downgrade Mitel 622 / 612 for older systems / SW

[NilsG]

i saw a lot of posts on how to downgrade an 600 DECT phone. so i thought i do a little guide.

1: prex "esc" 2 times
2: prex the >>> key
3: type: ""***76# "
4: in the menu that appears go to "Download settings"
5: in the next menu gå to the bottom and you see "Switch to... 133.033.031" select and press ok.

Note: This software version is flawed, when starting the phone you must hold the on/off key longer than normal, wait until the phone is completely started until you release the key.
i have tested this version on old 300 system and also on even older ascotel systems. and on older SW versions of the 400 family.

[Jerome Clamot]

Hi,

I have to register some 622d on a mitel 400. I need to downgrade the hansdets. If i follow your topic, it succeed for some but not for the others. I don't get switch to 133.033.031 but switch to 7.4.5.
Can you help me ?

Thanks