Set time date Meridian Norstar M3820 - Nortel Meridian M3820 Corded Phone

Try another 4 wire phone cord from the wall jack to the phone it is possible that you have a bad cord. These phones will only work with a Meridian System .2 wires are line ,the other 2 wires are power to the phone. If you have another phone try plugging it into the same wall jack to check the jack/line itself. Anything else would be a defective phone/ lcd ( note you can have dial tone without display, but the unit will only access one line.

Bad set or bad port on phone system.
Call a tech in to check if another set will not work at same jack.

Depends on which system you have. M7310 is just the phone model which is compatible with all norstar meridian systems.

The easiest way (which only works on one of the phone system models) is to dial Feature ** TIME
and use 23646 as the password. If feature **TIME doesn't work for you, it might be best to do it with someone over the telephone since it can be slightly tricky.

When you connect a Nortel Meridian M3820 phone to a 3300 CITELlink Gateway andprogram it as a CITELlink Type2 device, ... Button Label. Function ... Feature Key 4. 11. Feature Key 5. 12. Feature Key 6. 13. Program. 14. Menu Right

The time and date comes from the Norstar KSU not from the phone.

how do I change the time on the phone from 24 hour clock to 12 hour clock

Press "Program" button
Press "Right Arrow" button until you see "Time and date set"
Press "Hold" button
Enter the current information
Press "Hold" button
Finally press "Rls" button and the correct information will show on display

Unplug the phone for 1 minute and then reconnect it. After booting up, it should correct the problem.

http://www.best4systems.co.uk/_design/best4systems/_pdf/Phones/Meridian_Option/Meridian_Norstar_M3820_M3310_M3110.pdf

Above is your manual this should sort things out.

Feature *6