Kramer Electronics SG-6 user manual Video Signal

Figure 12: SG-6N Fuse Location

10.2 Video Signal

Problem

Remedy

No video at the output

1.

Confirm that your source and output devices are powered on and

device

connected properly. The input of your machine should be of an identical

signal format at the output of your source. Signals at the output of your

machine should be of an identical signal format as at the input of your

display.

2.

Confirm that any other device in the signal path have the proper input

and/or output selected.

3.

Use the Video Tester to help trace faulty cables and equipment (see

section 4.1).

Video level is too high or

1.

Verify that the lines are well matched through 75ohm impedance;

too dim.

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 are "rolling"

Hum bars (ground loop) are caused by a difference in the ground potential of

up or down in the output

any two or more devices connected to your signal path. This difference is

image

compensated by passing that voltage difference through any available

or:

interconnection, including your cables.

WARNING!

Low Frequency Hum in

Do not disconnect the ground from any

the output signal

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.

4.

Use a video Isolator, such as Kramer OC-1N or a differential amplifier

such as Kramer 123V inserted in the video signal path.

Kramer Electronics Ltd.

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