Zeiss humphrey HFA II-i series, Field Service Manual

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Adjustment / Calibration Humphrey Field Analyzer II - i
Confidential and Proprietary
Field Service Guide
4 - 40 52235C1105
FIGURE 4-13. Z-Axis CRT Driver Board Adjustments
CRT Yoke Adjustments
WARNING: During these adjustments you will be working closely
around the back of the CRT with power applied. Work carefully
to avoid the areas where the CRT high voltage is present.
NOTE: Use the operator panel extension/support tool and extender cables as required to
gain access to the yoke and magnet adjustments.
Yoke Rings
Adjustment of the yoke rings (Figure 4-14) should seldom, if ever, be necessary.
Adjustment should be done only if needed to obtain small additional horizontal or
vertical display movement after all other CRT adjustments have been made. Yoke ring
adjustment does not affect size of the display image.