The Norstar M7208 on my colleague's desk appears to be set for another language. How can we change this back to English?

If you have lines appearing on your phone and they don't ring you need to program lines to ring. This type of programming is done from a M7310 phone. Page 323 of this manual shows how to program this on a NorthStar MICS Ver 6 phone system.
http://pdf.textfiles.com/manuals/TELECOM-F-R/Nortel%20MICS%20System%20Installer%20Guide%206.1.pdf

Enter the programming mode : Feature **266344
Password:266344
You will have 4 programming buttons on your phone, normally the 2 top left and 2 top right of the 2 vertical rows.
top left = move up one level
lower left = back
top right = select
lower right = next
once you enter the programming mode press next to "Terminals and Sets"
press select
enter your extension number
press select
press next to "Line Access"
press select
press next to "Line Assignment"
press select
use the next key to go to the line you want and use the soft-key below the display to change it from "Appear" to "Appear and Ring"

Hello Didi,
Try this site ...
http://btbusiness.custhelp.com/euf/assets/TelephoneSystems/Norstar/HTML/compactmanual/infod.htm
k

This is tech side of programming and not Admin, if you don't know config password or how to program then call a tech.
If you do know then:
First find out what line #, do F*0 then press the button and note the full number on the display.
i.e. Line 5 in programming is Line 005, 025 or 031 depending on software version.

Sets/LineAccess/LineAssignment/Show line ***/Change to Appear Only or Not Assigned.

Does it ring when you move it to a known ringing port? Is it programmed to ring (Terminals & Sets) Appear and Ring? Do you have Automatic Set Relocation turned on so the extension number stays with the phone?

There are a lot of features to check for ringing, including the volume of the set.

Carl

Press feature *501

No, the M7208 is a propriatary set which requires the PBX to function, whereas the aastra phone is a stand alone set which requires a standard telephone line and a power source.

Programming is done on M7310, M7324 and T7316 sets.
To set up ringing you need to enter programming by pressing the feature key followed by **266344.When prompted to enter the password enter 266344.
The screen should say TERMINALS&SETS. The 4 top line/feature keys are now used for programming.
At the terminals&sets prompt, press the show key (top right arrow). The display should now ask for an extension number. Enter extension number you wish to program ringing on. Press the show key (top right arrow)
The display should sat LINE ACCESS
Press the show key (top right arrow) .
The display should say LINE ASSIGNMENT.
Press the show key (top right arrow) .
The display ask for a line number. press list
The display should sat line 001: appear only press CHNG til it says appear &ring.
press next key (lower right arrow)
The display should say line 002: appear only
Repeat same procedure as line 001 til all available lines are done
press the release key when finished

Have you tried:

Feature **23646 password 23646 (if you phone admin hasn't changed this) and then select set day& time then change there

There is a built-in feature called Set Relocation. Check with your system administrator to make sure this feature is set to No. Then you can swap phones without a problem. Good Luck!

Increase the contrast of display of ur phone it might fix the problem