Pioneer PDA-5002, Service Manual

Page: 112 / 183

112
PDP-503CMX, PDP-503MXE, PDA-5002
SUS-B Ground Timing Adjustment
It is necessary to readjust this adjustment when replaced the X or Y DRIVE Assy and the pulse module.
Measurement point and method
Measurement point of waveform of X and Y DRIVE Assy in timing adjustment is test pin of SUSOUT of the pulse module of
bottom of the main unit.
X DRIVE Assy : K3106 Y DRIVE Assy : K2203
Measurement screen : White mask
The measurement is easy to perform when turns field AB alternation to OFF. (RS-232C command: OCN)
Measure a sustain pulse of the fourth pulse (X DRIVE) and the fifth pulse (Y DRIVE) from the back of the fourth FS, and
adjust. In the start section of this sustain pulse, waveform has inflection point with the timing when SUS-B becomes ON.
Adjust so that the voltage of this inflection point is the nearest to 150V and do not become less than 150V.
Adjustment parameter
X DRIVE: XSUSB (RS-232C command : XSB)
Y DRIVE: YSUSB (RS-232C command : YSB)
Note:
• Connect GND of probe measuring waveform to SUSGND terminal by all means.
• Precise waveform is not displayed, and an adjustment gap may occur that does not collect GND properly.
Waveform in the measurement
CH1 : Y SUSOUT (K2203), 50V/div
CH2 : X SUSOUT (K3106), 50V/div
CH4 : YPR-U1 (K2038)- Trigger, 5V/div
Trigger : 2msec delay
Rst
1ms/div
X X X X X X Y Y Y Y Y Y
5
µ
s/div
Magnify 4SF block
Measure a waveform of this section and adjust.
Magnify the fourth pulse sustain pulse (XSUSOUT waveform) from the back of the above waveform.
1SF 2SF 3SF 4SF
OK
NG
150V Line
GND
50V/div
100msec/div
50V/div
100msec/div
150V Line
This broken section moves by
changing the adjustment
parameter.
Become less than 150V.
→
NG