TROUBLE SHOOTING GUIDE
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, testing after each set to see if the fault has
re-appeared.
No speech from door panel :
Check terminal 2 on the amplifier for continuity
back to the sentry 1 PCB. Check terminal 2 on the handset for continuity back
to the sentry 1 PCB.
No speech from handset :
Check terminal 1 on the amplifier for continuity
back to the sentry 1 PCB. Check terminal 1 on the handset for continuity back
to the sentry 1 PCB.
Handset bleeps only once :
Check the voltage across terminals 3 & 4 on the
door amplifier. This voltage will be 12V DC when a call is activated.
Handset rings for only 1 second :
Check terminal 1 of the amp for
continuity back to the sentry 1 PCB. Check terminal 1 of the handset for
continuity back to the sentry 1 PCB.
Phone does not stop ringing when handset is lifted :
Check terminal 2 on
handset for continuity back to the sentry 1 PCB.
Lock will not operate :
Check the relay is activating on the sentry 1 PCB (If
it is not, check terminal 5 on the handset for continuity back to the sentry
PCB). Check the voltage across the release when the relay is activated).
Lock operates as soon as the handset is lifted :
There is a short between
terminals 5 and 2 on the handset cables.
When any button is pressed nothing happens :
Check the CB connection
on the sentry 1 PCB (The voltage on this terminal should be +12V DC). Also
check this at the door panel.
No calltone to the handset (speech and lock ok) :
Check terminal 4(T) on
the handset for continuity back to the sentry 1 PCB.
Hum on the speech lines :
Check the intercom cables are not running close
to any high voltage or mains cables.
