Akai AP-Q310

Vill. ELECTRICAL ADJUSTMENT
IC |
TC9I42eP
OFF -SET
VOLTAGE
G 2
VR3 VR2
F4 F3
IC2 LA6458S
CS
VRI
J!
Tomer Ge
DIFFEREN
10987654321
1. OFF-SET VOLTAGE ADJUSTMENT
(VR2, 3) AND TORQUE DIFFERENCE
ADJUSTMENT (VR1)
1) Disconnect the motor connection cord (J1).
2) Short connector (J1) pins (7), (8) and (1).
3) Set VR1 to the center.
4) Turn the power switch ON.
5) Connect an digital voltmeter to terminal (10) of con-
nector JJ and adjust VR3 until it reads —-120 mVDC.
6) Turn the power switch OFF.
7) Short connector (J1) pins (4), (5) and (1).
8) Turn the power switch ON.
9) Connect a digital voltmeter to terminal (9) of con-
nector J1 and adjust VR2 until it reads -—120 mVDC.
10) Turn the power switch OFF and connect the motor
connection wire to connector (J1).
11) Connect an oscilloscope to (9) and (10) of connector
(J1).
12) Turn the power switch ON.
13) Set the SIZE/MANUAL selector to MANUAL.
14) Turn the power switch ON to rotate platter.
15) Adjust VR1 so that the voltage of connector (J1)’s (9)
and (10) may be the same. (The voltage indicated in
(9) and (10) is for switching motor coil, and its fre-
quency is very low.
14
Fig. 9 Quartz Servo PCB (Parts side View)
2. WOW AND FLUTTER CONFIRMATION
!) Playback the test record (3,000 Hz).
2) Confirm that the Wow and Flutter is within 0.03%
GIS).
3) It not, re-adjust VR1, VR2 and VR3.