JVC Model 200 service manual Image out of focus, Picture Geometry, XY Convergence

Chapter 5---Troubleshooting

Table 5-3. Troubleshooting Guide (continued)

PROBLEM	CHECK	POSSIBLE SOLUTION	SECTION
Arc Lamp	Brightness flicker or	Arc Lamp may have too	4.4
	picture is very dim.	many hours of usage.
		Replace Arc Lamp.
Image out of focus	Spacer balls not visible.	Perform the Projection	User’s Guide 5.5.15
		Lens Focus procedure.
	ILA® “spacer balls” are	Perform the CRT	3.5
	visible but the image is	Mechanical Focus
	fuzzy.	procedure.
	CRT focus range is	Adjust the Electronic	5.6
	limited and the image is	focus.
	fuzzy.
	CRT focus in not	Ensure the ILA®	4.16
	effective.	assembly is installed
		correctly.
	Image blurry with	Replace ILA® assembly.	4.16
	shadow on right edge.
	Characters do not	Replace ILA® assembly.	4.16
	appear legible.
	CRT focus problem is	Replace CRT.	4.15
	limited to one color.
	Sensitivity Offset is set	Reset Sensitivity Offset.	User’s Guide 5.9.2
	too high.
Picture Geometry	Picture not centered or	Repeat the Blanking,	User’s Guide 5.4.3,
	sized correctly.	Phase, Size, and	5.4.4, 5.5.1, 5.5.2.
		Centering procedures.
	Picture “wraparound” at	Readjust Blanking and	User’s Guide 5.4.3,
	left or right edge.	Phase.	5.4.4.
	Retrace lines on raster.	Adjust TOP Blanking.	User’s Guide 5.4.3.
	Image not squared.	Check Geometry and	User’s Guide 5.5.3,
		readjust if necessary.	through 5.5.10.
	Image bowed at left/right	Check Bow, Pincushion	User’s Guide 5.5.3,
	edge or top/bottom.	Balance, and Pincushion	5.5.4, 5.5.10.
		adjustments.
	Picture Linearity.	Readjust Horizontal,	User’s Guide 5.5.7,
		Vertical, or Edge	5.5.8.
		Linearity.
XY Convergence	Linearity is different	Yoke not properly set on	3.6
	between colors. Unable	CRT. Perform CRT
	to converge.	Rotation procedure.
	Horizontal size is	Adjust horizontal coils on	3.10
	different between colors.	Scan Reversal Board.
	Vertical size is different	Adjust vertical size pots	3.10
	between colors.	on Horizontal/Vertical
		Deflection board.

Table 5-3. Troubleshooting Guide (continued)

Model 200 Service Manual 5-7