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.
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