Adjustment Procedures - Mitsubishi Electric XD8100U Service Manual

Adjustment Procedures

[A/D Pre-Amplifi cation Circuit]
1. ADC offset/gain adjust-
ment
Measuring
-----
instrument
Test point -----
-----
EXT trigger
-----
Measurement
range
Shown in the table
Input signal
below
COMPUTER /
Input terminal COMPONENT
VIDEO-1 IN terminal
No. Pattern
29 White/black raster
30 SMPTE (White)*
* Though the signal generator
supplies this signal as a green
signal, the projector receives it as Y/
C /C signal. Therefore, this signal
B R
is projected as a full white SMPTE
signal.
Adjustment purpose To adjust the DC level and amplitude of the video signal at the time of ADC input.
Symptom when
Solid black, solid white, or incorrect color phase appear in the projected
incorrectly adjusted
image.
* Enter the adjustment commands in capital alphanumeric letters.
1. Connect the projector with a PC running Microsoft
operating system. (Refer to the fi gure on page 1.)
2. Start Microsoft
3. Start the communication program [Hyper Terminal] on Microsoft
Me/XP to open the Hyper Terminal window. (Refer to Hyper Terminal Setting on
page 2 for the settings.)
Offset/gain adjustment with the RGB signal supplied
4. Supply an XGA signal (White/black raster No. 29).
~
5. Enter [00 5] (the command for RGB input offset/gain adjustment) on the Hyper
Terminal window, and the adjustment proceeds automatically.
6. When the adjustment fi nishes, the return command [00
Hyper Terminal window. The last three digits of the return command indicate the
adjustment results of R, G, and B respectively from the left by 1 or 0. When the
adjustment has succeeded, 1 is displayed. When it has failed, 0 is displayed.
Possible causes of failures in the adjustment are errors on the PCBs, wrong
signals, and wrong input selection.
Offset adjustment with the component video signal supplied
7. Supply an NTSC signal (SMPTE (White), No. 30).
~
8. Enter [00 AC1] (the command for video input clamp adjustment) on the Hyper
Terminal window, and the adjustment proceeds automatically.
9. When the adjustment finishes, the return command [00
the Hyper Terminal window. The last two digits of the return command indicate
the adjustment results of C
the adjustment has succeeded, 1 is displayed. When it has failed, 0 is displayed.
Possible causes of failures in the adjustment are errors on the PCBs, wrong
signals, and wrong input selection.
Windows 95/98/Me/XP.
® ®
and C respectively from the left by 1 or 0. When
R B
- 3 -
Windows 95/98/Me/XP
® ®
Windows 95/98/
® ®
~
5111] is displayed on the
~
AC111] is displayed on