IBM Telephone 412 Manual De Usuario

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4. Press [0], [1] for ON or [0], [0] for OFF. 
5. Press [MUTE]. 
6. A short ring will be heard to signal successful programming. 

NOTE: The default value is ON for all 4 lines. 
 

There are 3 levels of volume adjustment (low, middle, and high) for the ringer. 

1. Press the [VOLUME] key (beneath the dial keys) up or down when receiving a call or when the 

phone is idle. 

1. Press the [SPKR] key. 
2. Press the [VOLUME] key up or down to the desired volume level. 

There are 3 volume levels (low, middle, high). As the handset or headset is in use, adjust the volume by 
pressing the [VOLUME] key up or down to the desired volume level. 
NOTE:  The default level is the low level. A short ring will be heard when the volume is set at the  maximum