Drive Assy Adjustment - Pioneer PDP-434CMX Service Manual

5

6.2 DRIVE ASSY ADJUSTMENT

How to readjust the timing of the control signals when the DRIVE Assy TND506MD is
to be replaced
As there is a large difference in delay time among the individual TND506MDs, timing adjustment has been made on each
TND506MD in the unit process. If the TND506MD is replaced on the X or Y Drive Assy, readjustment of the timing of the
control signals is required.
Assy Replaced IC
IC1101
X DRIVE
IC1102
IC2201
Y DRIVE
IC2202
• How to adjust
Adjust the timing between the startup of the control signals of SUS-U1, SUS-D1, SUS-U2, and SUS-D2 and the startup
of the voltage between the gate and the source of the output FET, with the VR resistors that are inserted in the signal
line in series. When adjusting, set the unit to Drive OFF mode, and Vsus to 0 V. (For details on how to set to Drive OFF
mode, see "7.1.5 Power on/off function for the large-signal system".)
• Specified values for adjustment and adjustment points
Set Value for
Signal Name
Delay Time
375ns ± 10ns
SUS-U1
375ns ± 10ns
SUS-D1
375ns ± 10ns
SUS-U2
375ns ± 10ns
SUS-D2
Note: Connect GND of the probe with DGND (DGND: X Drive Assy: K1020, Y Drive Assy: K2010) for input signal.
For outputting a signal, obtain a signal from the FET gate terminal.
For adjustment, magnify any pulse in the waveform.
Waveform of the
control signal
(input signal)
VGS waveform
(output signal)
• Actually measured waveforms
Input signal: 1V/div
Output FET VGS 5V/div
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6
Signal for which Readjustment is Required
XSUS-U2 & XSUS-D2
XSUS-U1 & XSUS-D1
YSUS-U1 & YSUS-D1
YSUS-U2 & YSUS-D2
X DRIVE
Input Output
Signal Signal
K1005 Q1108
K1009 Q1112
K1008 Q1103
K1006 Q1105
Adjust so that the delay is
in the range of 375 ± 10 ns.
500us/div
VGS=5V line
PDP-504CMX/1
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7
Input
Adjustment
Signal
VR
VR1103 K2025
VR1104 K2027
VR1101 K2022
VR1102 K2024
About 2.5V
Magnify.
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8
Y DRIVE
Adjustment
Output
VR
Signal
Q2202 VR2201
Q2205 VR2202
Q2208 VR2203
Q2212 VR2204
50ns/div
8
A
B
C
D
E
F
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