Trouble Shooting Guide - Videx SENTRY 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.
SYMPTOM
No speech from door panel
No speech from handset
Handset beeps only once when called
Handset only rings for 1 second
Phone does not stop ring when handset is
lifted.
Lock will not operate from telephone
Lock operates as soon as the handset is
lifted.
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TEST
Check terminal 2 on the amplifier for continuity back
to the sentry PCB
Check terminal 2 on the handset for continuity back
to the sentry PCB
During a call but before lifting the handset, check the
voltage to the telephone on terminal 2 is 12Vdc.
Trace this voltage from amplifier terminal 2 to the
telephone.
Check the voltage drops to approx. 1Vdc during a
call 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 amplifier for continuity back
to the sentry PCB
Check terminal 1 on the handset for continuity back
to the sentry PCB
During a call but before lifting the handset, check the
voltage to the telephone on terminal 1 is 12Vdc.
Trace this voltage from amplifier terminal 1 to the
telephone.
Check the voltage drops to approx. 4Vdc during a
call after the handset is lifted. (If not try another
telephone)
If all else fails try another amplifier at the door station
Check the voltage across 3&4 on the door panel
amplifier. During a call this should be 12Vdc
(Supplied from the Sentry PCB)
Check terminal 1 going to the handset for continutity
back to terminal 1 on the door station via the Sentry
PCB.
Check terminal 2 on handset for continuity back to
the Sentry PCB.
Check terminal P on the telephone for continuity
back to the Sentry PCB.
Check the voltage on terminal 5 of the handset. 5Vdc
in standby dropping to 0V when the release button is
pressed during a call.
Check for shorts across terminal 5 of the telephones
and other cables.
Check terminal 5 voltage. Should be 5Vdc when the
button is not being pressed (5V is generated by the
Sentry PCB).
SENTRY TECHNICAL MANUAL VER1.6