Alpha Communications VM25WH Series Installation And Use Instructions Manual page 3

Special Note About CALLING HANDSET TO HANDSET:
It is important to lift the calling handset off of its cradle, BEFORE
depressing the push button to call the other handset station. If you
depress the push button first, and then lift the calling handset
cradle, the door station(s) will not be disconnected and the inside
conversation may be heard at the door station(s). This is due to the
fact that when the handsets are hung-up, the relay that disconnects
the door station is dis-engaged and re-enables conversation at the
door station(s).
TROUBLESHOOTING
If the system fails to operate as required, review operating
instructions again. If the equipment fails to operate as
indicated in the instructions, check the following points:
1. ENTIRE SYSTEM DEAD: Check for 16VAC at the
two (2) transformer secondaries; wiring between trans-
former and amplifier/power supply unit(s); connections at
main power supply units, 117VAC at transformer pri-
mary, and check the (3 amp slo-blo European size) fuse
in the VRU power supply. If fuse is blown, replace with
our model #50T-3A.
NO CALL UP CHIME AT HANDSET: Check for
2.
approx. 16VAC at terminals 'O' and 'R' on HT2006
handset, when entry station pushbutton is depressed.
Temporarily switch handset with one from a functioning
location. Check wiring connections at handset. Tempo-
rarily switch handset to another location that is function-
ing, and try again. Check that entry station pushbutton is
making contact, by shorting out the two (2) wires on the
back of the button. Check that the R2006 AlphaTone™
chime module is seated properly on the multi-pin connec-
tor or replace with one from a functioning handset
location.
NO BUZZER BETWEEN HANDSETS: Check for
3.
approx. 16VAC at terminals 'Z' and 'S' (on HT2006
handset), when called from another handset. Temporarily
switch handset with one from a functioning location.
Check wiring connections at handsets. Temporarily switch
handset to another location that is functioning, and try
again. Check that wiring inside handset base is not
restricting movement of buzzer clapper. Replace handset
or buzzer with one from a functioning handset location.
4. NO PICTURE AT MONITOR: If screen is NOT
LIGHTING UP, check for approximately 16VDC at(+)
and (-) terminals on monitor PC board (VH250E or
VH250P). Check Brightness and Contrast controls on
front of monitor. If screen IS LIGHTING UP but there is
no picture, you probably are not getting a video signal from
the camera to the monitor. Starting at camera, check for
video signal through coax cable, and through (VDU-4)
video distributors (if used). Check for approx. 12VDC
power at each VDU-4 video distributor (if used). Check
coax connector at camera(s) to make sure it is not shorted
or open. Temporarily switch monitor PC board (VH250E
or VH250P) with one from a functioning location.
5. NO VOICE ON SYSTEM: Check volume control
potentiometer on NH208TVU amplifier. Check terminals
'T', 'O', and 'M' to handsets. Check speaker/microphone
connections at each entry station. Disconnect terminals
'T', 'O' and 'M' to system amplifier, and connect a single
handset to those terminals. If voice is working, amplifier
and entry speaker/microphone are O.K., so check riser
wiring. If not amplifier or speaker/microphone could be
faulty. Check by replacement.
6. UNABLE TO RELEASE DOOR STRIKE: Check wiring
to handset terminals 'E' and '(1-5 or 1-10 depending upon
which one you are using for door release)'. Temporarily
remove door opener wire going to handset terminals '(1-
5 or 1-10)' and touch to terminal '8V' on NH208TVU.
Check operating voltage of door opener matches output
from system amplifier. Check wiring (and gauge) to door
opener, from amplifier/power supply. When using a
magnetic type lock or other 'fail-safe' type door lock, you
should use a reversing relay, such as our model# PK407A
for each entrance.
7. HUM OR BUZZ: Check system wiring installed too
close to power wiring or electrical devices or transform-
ers; check transformer(s) installed too close to control
equipment (should be at least three (3) feet away). Wiring
is being run next to wiring for other systems and/or
devices.
8. SQUEALING OR HOWLING: Check wiring for pinch-
ing, crimping, crushing, shorting, or being too close to
another source of audio interference. Make sure correct
voltage transformer is being used to power the NH208TVU
amplifier.
9. MONITORS TIMING OUT TOO QUICKLY:
Check adjusting control potentiometer on VH250E (or
VH250P) PC board and adjust as needed from approx. 0
to 180 seconds. Calibration is not exact, so please check
timing after re-adjusting.
10. MONITORS DO NOT TIME OUT AT ALL:
Check for shorts and/or grounds on system. Temporarily
switch monitor with one from a functioning location.
Check that entry station pushbutton is not stuck or
shorted. Temporarily switch monitor PC board (VH250E
or VH250P) with one from a functioning location.
NOTE: If these checkpoints fail to indicate the prob-
lem, there may be an equipment fault. Contact the
factory or qualified service representative.
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