Check Of Zoom Track; Spot Noise; Spot Noise Adjustment - Hitachi VK-S454 Service Manual

(3) Check of Zoom Trace
Incompleted Phenomenon:
Focus is lost during zooming.
Condition:
Point at the backfocus chart, 1500 ± 5mm away from the lens surface.
Light the backfocus chart with 200 - 400 lx.
Caution when Adjustment:
1) Measure the distance between the chart and lens surface precisely.
2) Place the chart as parallel as possible to the lens surface.
3) The backfocus chart should always be at the center of the monitor screen when the zoom is set to the wide-angle
and telephoto ends.
4) Do not place any obstruction between the lens and chart during adjustment.
Procedure:
1) Input 3 to PC on the AF menu screen.
2) Follow the instructions on PC display thereafter.
If error message appears, readjust the following items:
(1) Zoom/Focus Tracking Adjustment
(2) AF Noise Level Adjustment

5.5 Spot Noise

Important:
Spot noise refers to bright points that appear on the screen, which are caused by a defect in pixel of CCD image sensor.
Perform this adjustment after specified components have been replaced (see "List of Adjustment Items").
Perform this adjustment if spot noise occurs under abnormal usage conditions or after long-term use.
If spot noise still occurs after this adjustment is complete, the CCD image sensor may be defective.
Perform this adjustment after completing all other adjustments. (Perform this adjustment in normal video status.)

(1) Spot Noise Adjustment

Incompleted Phenomenon:
Spot noise occurs under abnormal usage conditions or after long-term use.
Equipment:
Color video monitor (CRT type is desirable)
Condition:
Cap the lens (so that no light enters).
PC Display & Figs
Main menu
***********************************************************
MANUAL ADJUSTMENT PROGRAM
***********************************************************
[A] DATA INITIALIZE
[B] ELECTRIC VOLUME
[C] ADJUSTMENT
[D] AUTO FOCUS
[E] SPOT NOISE
[F] IR CONTROL
[ESC] END
Please select [A] - [F] or [ESC]
3 - 10
AF menu
***********************************************************
AUTO FOCUS ADJUSTMENT
***********************************************************
[1] ADJUSTMENT OF ZOOM/FOCUS TRACKING
[2] ADJUSTMENT OF AF NOISE LEVEL
[3] CHECK OF ZOOM TRACE
[ESC] RETURN TO MENU
Please select [1] - [3] or [ESC]