Extron electronic 450 Plus Series manual Optimizing the Audio Audio Switchers, Troubleshooting

Operation, cont’d

Optimizing the Audio (Audio Switchers)

Each individual input audio level can be adjusted within a range of -18 dB to

+24 dB, so there are no noticeable volume differences between sources and for the best headroom and signal-to-noise ratio. Adjust the audio gain and attenuation as follows:

1.	Connect audio sources to all desired inputs and connect the audio outputs to
	output devices such as audio players. See “Audio input and output
	connections (audio models only)”, in chapter 2, “Installation”. For best
	results, wire all of the inputs and the outputs balanced.
2.	Power on the audio sources, the switcher, and the audio players.
3.	Switch among the inputs (see “Creating ties”, in this chapter), listening to the
	audio with a critical ear or measuring the output audio level with test
	equipment, such as a VU meter.
4.	As necessary, adjust the input audio level of each input (see “Viewing and
	adjusting the input audio level (audio models)”, in this chapter) so that the
	approximate output level is the same for all selected inputs.
5.	As necessary, adjust the output audio level of each input (see “Viewing and
	adjusting the output volume (audio models)”, in this chapter).

Troubleshooting

This section gives recommendations on what to do if you have problems operating the CrossPoint 450 Plus or MAV Plus switcher, and it describes an actual image problem that Extron has encountered.

General checks

1.	Ensure that all devices are plugged in and powered on. The switcher is
	receiving power if one of the front panel Power Supply LEDs is lit green.
2.	Check to see if one or more outputs are muted.
3.	Ensure an active input is selected for output on the switcher.
4.	Ensure that the proper signal format is supplied.
5.	Check the cabling and make corrections as necessary.
6.	Call the Extron S3 Sales & Technical Support Hotline if necessary.

Plasma display S-video problem (CrossPoint 450 Plus switchers only)

Extron has encountered a problem when a CrossPoint 450 Plus switcher routes S-video that is output by some video conference codecs. Some codecs change the DC offset on the chrominance (C) so that it is very different from the level on the luminance (Y). This can cause a plasma display to come up in the wrong size mode.

With the matrix switcher taken out of the system, the plasma works fine. It looks like a problem with the matrix switcher, but it is not. The matrix switcher boosts the bad codec output, which makes the plasma go to the wrong setting.

Solution: Try placing an Extron video DC block adapter, part #26-495-01, on the luminance (Y) input to the switcher from the codec.

3-56 CrossPoint 450 Plus and MAV Plus Switchers • Operation