JVC QL-A2 - Service Manual

JVC
MODEL
OL:-A2
QUARTZ AUTO-RETURN
TURNTABLE
No.2444
JAN. 1978

Summary

1. Specifications

2. Service Precautions

3. Features

4. How to Operate (Names and Functions)

5. Operation of Automatic Mechanism

6. Block Diagrams

6-(1) Servomotor Control System

Illustrates the servomotor's speed control system architecture.

6-(2) IC802 Integrated Circuits and Waveforms

Details the IC802 circuit and its associated signal waveforms.

7. Troubleshooting

7-(1) Platter does not rotate

Guide for diagnosing and resolving issues where the platter fails to spin.

7-(2) Platter rotates at high speed

Guide for diagnosing and resolving issues of excessive platter rotation speed.

7-(3) Rotation is not locked to the crystal oscillator frequency

Guide for diagnosing and resolving speed lock issues.

8. Cartridge Replacement

9. Adjustment Procedures

9-(1) Power Supply Voltage Check

Procedure to verify the servomotor's power supply voltage.

9-(2) Lock Adjustment

Method for adjusting platter speed lock using an oscilloscope.

9-(3) Overhang Adjustment

Process for setting the tonearm stylus tip's correct overhang position.

9-(4) Tonearm Lifter Height Adjustment

Procedure for adjusting the height of the tonearm lifting mechanism.

9-(5) Auto-return (Lead-out) Adjustment

Steps to adjust the tonearm's automatic return function.

9-(6) Tracking Force Adjustment

Method for correctly setting the stylus tracking force.

9-(7) Anti-skating Adjustment

Guide for adjusting the anti-skating force according to cartridge type.

10. Lubrication

11. Exploded Views and Parts List

11-(1) Cabinet and Mechanism Assembly

Exploded diagram and parts for the cabinet and main mechanism.

11-(2) Mechanism Base Assembly

Exploded diagram and parts for the mechanism base.

11-(3) Knob Base Assembly

Exploded diagram and parts for the knob base.

11-(4) Tonearm Assembly

Exploded diagram and parts for the tonearm.

11-(5) Parts List with Specified Numbers for Designated Areas

Comprehensive parts list by region and specification.

12. Connection Diagram of TXX-124

13. TXX-124 Schematic Diagram

14. TXX-124 Printed Circuit Board Assy and Parts List

15. Packing Materials and Part Numbers

16. Accessories List

17. QL-A2 Schematic Diagram

JVC QL-A2 Specifications