Audio System Trouble Shooting Guide - Videx VANDAL RESISTANT Technical Manual

TROUBLE SHOOTING
When trouble shooting a large system, it will be easier to break the system down to a
manageable size. The simplest way to do this is to remove all but one handset. Doing this,
you can confirm the door panel and control cabinet are free from faults. Once this has
been confirmed you can reconnect the handsets in small sets (Floor by floor), testing after
each set to see if the fault has re-appeared.
AUDIO SYSTEMS
SYMPTOM
No speech from the door panel to the
telephone.
No speech from the telephone to the door
panel.
No speech in either direction
Lock will not operate from telephone
Nothing happens when any call button is
pressed
Hum on the speech lines
PAGE 22 of 24 AUDIO/VIDEO VANDAL RESISTANT TECHNICAL MANUAL
TEST
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
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
Check the 315mA fuse in the power supply
Check for 12Vdc across terminals 3 & 4 on the door
panel amplifier. This should be there all the time and
comes directly from the PSU.
Check terminal 5 on the telephone. This terminal
shorts to terminal 3 of the telephone when pressed
(Becomes 0V).
Check the common of the buttons 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.
Ensure all intercom cables do not run close to higher
voltage cables
Try another amplifier at the door panel.
VER1.1