Apple 550, 575, 577, 560, 500, 578 manual Test pattern is

Adjustments	Video - 14
	7 Using a hex-head plastic
	adjustment tool, adjust
	VG2 until the first bar
Gray Bars	in the test pattern is
	completely black and the
	second bar is barely
	visible.
	8 Set the sub-contrast
	control (SC) to the
	center position.