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VRDK1 TECHNICAL MANUAL
VER1.0
TROUBLE SHOOTING
AUDIO SYSTEMS
SYMPTOM TEST
No speech from the door panel to the
telephone.
Check terminal 2 on the amplifier for continuity to
terminal 2 on the telephone.
Before lifting the handset, check the voltage to
terminal 2 of the amplifier is 8-12Vdc. Trace this
voltage to terminal 2 to the telephone.
Check the voltage drops to approx. 1Vdc after the
handset is lifted. (If not try another telephone)
If all else fails try another amplifier at the door station
No speech from the telephone to the door
panel.
Check terminal 1 on the door panel amplifier for
continuity back to terminal 1 on the telephone.
Before lifting the handset, check the voltage to on
terminal 1 of the amplifier is 8-12Vdc. Trace this
voltage to terminal 1 to the telephone.
Check the voltage drops to approx. 4Vdc after the
handset is lifted. (If not try another telephone)
If all else fails try another amplifier at the door station
No speech in either direction
Check the 315mA fuse in the power supply
Check for 8-12Vdc across terminals 3 & 4 on the
door panel amplifier. This should be there all the time
and comes directly from the PSU.
Lock will not operate from telephone
Check terminal 5 on the telephone. This terminal
shorts to terminal 3 of the telephone when pressed
(Becomes 0V).
Nothing happens when any call button is
pressed
Check the common of the button has 13Vac present
at all times.
When a call button is pressed you should be able to
read 13Vac on terminals 3 & 6 of the telephone (6 of
the telephone comes direct from the call button). If
voltage is there then check/change the buzzer.
Hum on the speech lines
Ensure all intercom cables do not run close to higher
voltage cables
Try another amplifier at the door panel.
