1. Preparation
4. Connect the test pins to the oscilloscope as follows:
Pin 1 (DTVLD) - Channel 1 (CH1) on the oscilloscope
Pin 2 (COM2) - Ground
Pin 3 (XVIDEO) - Channel 2 (CH2) on the oscilloscope
5. Attach the test chart to the machine.
6. Connect the operation panel to the machine.
7. Enter the service mode and switch the LED array on (see section 2-2-13).
8. Set up the oscilloscope as follows:
CH2 (XVIDEO) - 0.2 V/div.
TIME - 1 ms/div.
Then, select CH2 (XVIDEO) on the oscilloscope.
9. The XVIDEO signal shows one of the waveforms shown below. One, two or three dropouts should appear at
‘‘A’’ and ‘‘B’’ depending on the vertical scan line position, and moire should appear at ‘‘C’’.
If this waveform cannot be seen on the oscilloscope screen, loosen the SBU securing screws and adjust the
SBU position until this waveform appears on the screen.
The moire sometimes does not appear on the screen unless the lens is well focused. So, if the moire does not
appear on the screen, go to the
‘‘Focusing’’
procedure first, then go to the
‘‘Horizontal/Vertical Scan Line
Adjustment’’
procedures.
If this waveform appears on the screen, go to the
‘‘Horizontal/Vertical Scan Line Adjustment ’’
procedures,
then check that the moire at ‘‘C’’ satisfies the criterion in the
‘‘Focusing’’
section.
Test Chart attached on the Pressure Plate
Scan Start Line
"A" part
"B" part
"C"(8 lines/mm) part
"A" "B" part
Scan Line
2 dropouts
3 dropouts
1 dropout
4-13
