JVC 340 SC, 330, 370 SC service manual Adjust Contrast and Brightness

Chapter 5---Troubleshooting

Problem and	Possible Solution	Service	Operator
Symptom to		Manual	Manual
Check
Bright Red, Green	Adjust ILA® Assembly Bias	3.6	4.10
or Blue area on	and SHADING.
screen limited to
corners or edge.
Gray scale green in	Subtract Green SENSITIVITY offset,		4.10, 4.11
bright levels.	add Red and Blue.
Gray scale red in	Subtract Red SENSITIVITY offset,
bright levels.	add Green and Blue.
Gray scale blue in	Subtract Blue SENSITIVITY offset,
bright levels.	add Green and Red.
Picture—various
problems
Out of focus blurry	Clean oily spot off CRT, Prism, or
area on image	Projection lens.
limited to R, G,
or B.
Small dark line or	Scratch in optics or CRT burn.
dot in R, G, or B
image.
Bubbles in R, G, or	Replace affected ILA® assembly.	4.12
B image.
Image Ghost on	Replace Burn-In CRT or ILA®	4.7, 4.12
video.	assembly.
Reversed ghost	If projecting through glass, prevent
image on screen.	light
	from reflecting back into the
	lens
Picture lacks depth	Adjust Contrast and Brightness.		4.12.1,
of field.			4.12.2
Video jitter and	Replace Video Processor Board.	4.11
noise.
Video jitter present	Replace Raster Timing Generator.	4.11
at only one
source.
Video image is not	Level projector or rotate CRT	3.2
level.	Yoke.
Black band at top of	Remove air bubbles from Prism.
video.

Model 330, 340SC, and 370SC Service Manual 5-12