Guardian Technologies HR70 ユーザーズマニュアル

 

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Note: The only field repair permitted is to change the Tone/Pulse setting and 
the replacement of fuses.  All other repairs or alterations must be carried out by 
Guardian Telecom or an Authorized Service Depot.  See Warranty and 
Disclaimer for details. 

 
 

•  Disconnect the telephone from Tip and Ring power supplied by the PABX or 

central office before attempting to replace the fuse. 

•  Carefully remove the front cover assembly and separate from the housing 

by disconnecting the harness plugs.  NOTE that the handset and all 
electronics are attached to the front plate.

 

•  Replace fuse in fuse holder with a 0.25 amp 250V 3AG fast blow fuse. 

•  Carefully replace the front plate and install all eight screws.  Do not over 

tighten the cover screws, there is a flexible gasket between the cover and 
the body.  Excessive tightening of the screws deforms the gasket and 
reduces the weather resistance of the set. 

WARNING! 

•  Replace only with a 0.25 amp 250V 3AG fast blow fuse. Failure to do so will 

void the warranty. 

•  If, on reconnecting power, the fuse fails, check the telephone system wiring. 

The fuse protects the Tip and Ring line from the telephone system. It is 
usually powered at 48 volts DC and must not be connected to 120 volts AC.