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DIAGNOSIS AND TROUBLESHOOTING
5.1
GENERAL
All VIDEO TYPE modules have an auxiliary 75 ohm output connection point available on
the front edge of the module. This provides for simple connection of test equipment
when system commissioning or servicing is required. This test video output connector is
a 3 pin, 0.1" spaced, male IDC type, where the center pin is the active video output and
the other two pins are grounded.
This test video output on the modules gives the technician, total front panel access to all
video output channels in a switching system, without the need to remove or patch
connections on the rear of the video switching subrack equipment.
5.2
EXAMPLE FAULT ANALYSIS
As every system is different, only general techniques for fault location can be provided.
Fault location can be performed by using the procedures and applying them to the
actual block schematic for your specific system.
It is essential that the service engineer has a good operational knowledge of the specific
system in question. Remember that with the macros, the system features can be wide
and varied. First study the block schematic to understand the video paths, the modules
of concern, and their slot locations. A few hours spent on this at this point could save
many hours of frustration.
Remember that each video module has a monitor point on the front of it for easy access
of the test monitor. Every module has at least one LED indicator to show data flow to the
module and bi-directional modules have LEDs for data flow in both directions and CPU
fail indicators. LEDs show all normal operation actions and all abnormal operations
either by not flashing or flashing at the wrong time.
Do not forget to look at the error log file first. It is very useful for intermittent fault locating
as it may have logged the fault and the slot location in many cases.
5.2.1
No Video from One Camera
If a specific camera cannot be viewed on any monitor that had the correct source group
access, then check with a test monitor that video is present at the input to the sub-rack.
If so, move the camera cable to another (spare) input which will have to be programmed
for the required camera number PTZ details, etc. If it then works, then the input VDA
fitted to the back of the sub-rack is most likely faulty.
Rev. C
CHAPTER 5:
5-1
HMXMU01018
10/06
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