Hitachi CM615ET, Service Manual

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2
D. Geometry Distortion (All Preset Mode) :
1) The Contrast and Brightness control shall be properly adjusted at 20 F-L with full intensity reverse
pattern, then change to crosshatch pattern.
2) Pincushion distortion shall be less than H : 1.5% and V : 1.5%.
3) Barrel distortion shall be less than H : 1.5% and V : 1.5%.
4) Trapezoid and parallelogram distortion shall be less than H : 1.5% and V : 1.5%.
5) Distortion of four corners shall be less than 3mm x 3mm.
6) Parallelogram distortion shall be less than 2.0%
7) Tilt distortion shall be less than 1/2 degree when facing east and less than 1 degree when turning
around 360 degree.
8) Tilt distortion shall be less than 2 mm when facing east and less than 1 degree when turning around
360 degree The measurement of tilt is defined to measure the vertical axis with respect to the bezel,
the absolute value of the difference between the extreme left and right measurement of the center
horizontal line.
E. Alignment Procedure
E-1. Brightness Adjust:
Adjust the VR980, have the +15VS By 14.9V
±
0.1V (The voltage of the C944) in TIMING 1.
Check below items.
The voltage of C949 : 179
±
3V
C947 : 75
±
2V
C946 : 44
±
1.5V
C940 : 8.4
±
0.4V
P990 : 12
±
0.3V
Short-Circuit protection function check.
The power source is 230VAC input.
When short the C944, all output voltage should be shut down and unlatch.
When recover normal condition, all output voltage should recover automatically.