Kramer Electronics, Ltd.
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11.2 Video Signal
Problem
Remedy
No video at the
output device
1. Confirm that your source and output devices are powered on and connected properly.
The input of your amplifier should be of an identical signal format at the output of
your source. Signals at the output of your amplifier should be of an identical signal
format as at the input of your display.
2. Confirm that any other device in the signal path has the proper input and/or output
selected.
3. Use the Video Tester to test the video path leading to/from your amplifier (see
section 4.1" Video Tester")
Video level is too
high or too dim.
1. Verify that the lines are well matched through 75ohm impedances; otherwise it
results in a video level that is too high or too dim.
2. Confirm that the connecting cables are of high quality and properly inserted.
3. Check level controls located on your source input device or output display.
Noise bars "roll" up
or down in the output
image
or:
Low frequency hum
in the output signal
Hum bars (ground loop) are caused by a difference in the ground potential of any two
or more devices connected to your signal path. This difference is compensated by
passing that voltage difference through any available interconnection, including your
cables.
WARNING
!
Do not disconnect the ground from any piece of
equipment in your signal path!
Check the following to remove hum bars:
1. Confirm that all interconnected equipment is connected to the same phase of power,
if possible.
2. Remove equipment connected to that phase that may introduce noise, such as motors,
generators, etc.
3. Disconnect all interconnecting cables and reconnect them one at a time until the
ground loop reappears. Disconnect the affected cable and replace, or insert an
isolation transformer in the signal path.
11.3 Audio Signal (VM-9S only)
Problem
Remedy
No audio at the output
device, regardless of
input selected
1. Confirm that your sources and output device are powered on and connected properly.
Audio signals connected to the input of your switcher should be properly wired to the
output of your source. Audio signals connected to the output of your switcher should
be properly wired to the input of your line amplifier or recorder.
2. Confirm that any other amplifiers in the signal path have the proper input and/or
output selected. Pay special attention to input amplifiers that may be built into your
acceptor.
Audio level is too low
1. Confirm that the connecting cables are of high quality and properly built.
2. Check level controls located on your source input device or output display or
recorder.
