JVC Model 200 service manual Picture Color, Balance, Picture-Various, Problems

Chapter 5---Troubleshooting

PROBLEM	CHECK	POSSIBLE SOLUTION	SECTION
XY Convergence	Not enough range in Red	Adjust Red or Blue	5.5.11
	or Blue XY convergence.	CENTERING to match
		Green.
Picture Color	Red, Green, or Blue is	ILA® assembly bias	4.13
Balance	missing in the image.	voltage is incorrect or
		there is no signal-replace
		Video Amplifier Board.
	Red, Green, or Blue	Replace ILA® assembly	4.16, 4.13
	lacks color.	or Video Amplifier Board.
	Grey scale test pattern is	Readjust Contrast.	User’s Guide 5.11.2
	correct but image color is
	incorrect.
	Black image is	Adjust Threshold, Black	User’s Guide 5.10.2,
	overdriven.	level, and Brightness.	5.9.1, 5.11.1.
	Bright Red, Green, or	Adjust ILA® bias and	User’s Guide 5.7, 5.10
	Blue area on screen	shading.
	limited to corners or
	edge.
	Grey scale is Green in	Subtract Green	User’s Guide 5.9.2
	bright areas.	Sensitivity Offset and add
		Red and Blue.
	Grey scale is Red in	Subtract Red Sensitivity	User’s Guide 5.9.2
	bright areas.	Offset and add Green
		and Blue.
	Grey scale is Blue in	Subtract Blue Sensitivity	User’s Guide 5.9.2
	bright areas.	Offset and add Green
		and Red.
Picture-Various	Out of focus, blurry area	Clean oily spot off CRT,	3.12
Problems	on image limited to Red,	Prism, or Projection
	Green, or Blue.	Lens.
	Small, dark line or dot in	Scratch in optics or CRT	4.15.
	Red, Green, or Blue	burn. Replace CRT.
	image.
	Bubbles in Red, Green,	Replace affected ILA®	4.16.
	or Blue image.	assembly.
	Image ghost in picture.	Replace burn-in CRT or	4.15, 4.16
		ILA® assembly
	Reversed ghost image on	If projecting through
	screen.	glass, prevent light from
		reflecting back into the
		lens.
	Picture lacks depth of	Adjust Contrast or	User’s Guide 5.11.2,
	field.	Brightness.	5.11.1

5-8 Model 200 Service Manual