Alcad GRF-208 Instrucciones De Instalación página 21

Video system does not work in one monitor: auto switch-on,
screen doesn´t come on when receiving a call,..
Check that the ON/OFF switch for the video is in ON position
(on the left). Check that the red led of the monitor is on. Check the
connection between the connection bracket and the monitor. Check
that the voltage between + and – of the connection bracket is 14
± 15% Vdc. If failure cannot be found, there may be something
wrong with the monitor.
Poor image quality on all the monitors: distorted picture, ghost
images, loss of synchronisation.
In multiple access installation, check that you have only one
entrance panel defined as the main one. If splitters have been
used in the distribution, check that the voltage between + and –
of the splitters is 14 ± 15% Vdc. Check that coaxial cable line has
a 75 Ohm load: a) if tap-offs have been connected in series the
75 Ohm resistance must be removed from all the intermediate
tap-offs; b) with monitors in series cut the 75 Ohm resistances on
all the connection brackets, but from the one at the end of the line;
c) Check coaxial connection in splitters and tap-offs. If you cannot
find the fault, there may be something wrong with the video unit.
Check that resistences of 75 ohms are connected in the unused
terminals V2, M. If you cannot find the fault, there may be something
wrong with the video unit.
Poor image quality on one monitor: distorted picture, ghost
images, loss of synchronisation.
Check that coaxial cable line is charged with 75 Ohm: iwith
monitors in series cut the 75 Ohm resistances on all the connection
brackets, but from the one at the end of the line. If you cannot
find the fault there may be something wrong with the monitor.
Auto switch-on does not work on any monitor.
In multiple access installations, check that one entrance panel has
been defined as the main one and check connections D3 and D2
D I G I TA L V I D E O D O O R E N T R Y S Y S T E M S
Auto switch-on does not work on one monitor.
Blank screen on all the monitors.
Blank screen on all the monitors of a dwelling.
Blank screen on one of the monitors of a house or dwelling.
between different entrance panels. If you cannot find the fault
there may be something wrong with the audio unit.
Check that pushing the auto switch-on button the red led flash.
Check that the system is not engaged. If you cannot find the fault,
there may be something wrong with the connection bracket or the
monitor.
Check the connection between the video and the audio units.
Check that the coaxial cable to the monitors is connected to the
V1 and M terminals of the video unit. If this is the case, check
connections V2, M and V4, M of the video units of the installation.
If splitters have been used in the distribution, check that the voltage
between + and – of the splitters is 14 ± 15% Vdc. Check the
connections of the coaxial cable from the video unit to the monitors.
If failure is not detected, there may be something wrong with the
audio unit, video unit or any splitter.
Check the position of the J1 configuration jumper in the connection
bracket. Check coaxial's connection from the connection bracket
to the video unit. If splitters have been used in the distribution,
check that the voltage between + and – of the splitters is 14 Vdc
± 15%. If the fault cannot be found, there may be something wrong
with the tap-off of that floor or the splitter of he dwelling.
Check the connection between the connection bracket and the
monitor. Check the connections of the coaxial cable in the monitor's
connection bracket. If splitters have been used in the distribution,
check the position of the J1 configuration jumper in the connection
bracket. Check coaxial's connection from the connection bracket
to the video unit. If failure is not detected there may be something
wrong with the tap-off, connection bracket or monitor.