The Alpine 3DE-7886R is an in-dash 3-CD changer mechanism, designed to offer improved cost-effectiveness and functionality compared to older models. It boasts a compact size that allows for the integration of a tuner within its conventional dimensions. The mechanism's operation is controlled by two motors, two detection switches, and one Linear Position Sensor (LPS).
Function Description:
The core function of the 3DE-7886R is to manage and play multiple CDs within an in-dash car audio system. It features a "3D Shuttle" mechanism, which implies a sophisticated disc handling system. Key operational improvements include:
- Speed-up when changing the disc: This indicates a faster disc exchange process, enhancing user convenience.
- Realization of lower cost: The design aims to be more economical to produce.
- Digital servo mechanism: This feature improves the overall performance and characteristics of the disc playback.
The mechanism handles various operations such as magazine insertion, disc selection, tray magazine discharge, disc loading/unloading, and eject. These operations are precisely timed and controlled by the main control IC (IC601) and motor drive IC (IC702), in conjunction with the LPS and photo sensors.
Important Technical Specifications:
The manual provides detailed specifications for the main unit, including CD, FM, MW, and LW radio sections, as well as general electrical and physical characteristics.
CD Section:
- System: Optical (Compact Disc System), 16-bit linear system.
- Quantizing Bit Number: 2 channels.
- Channels: 0.5±2dB.
- Channel Balance (1kHz): 0.1%.
- Distortion (1kHz): 17Hz: 0±3dB, 127Hz: 0±2dB, 10.007kHz: 0±2dB, 19.997kHz: 0±4dB.
- S/N Ratio: 95dB.
- Separation (1kHz): 65dB.
- De-Emphasis (Ref. 1kHz): 4kHz: -20±3dB, 16kHz: -20±3dB.
FM Radio Section:
- Intermediate Frequency: 10.7±0.1MHz.
- Frequency Range: 87.5~108MHz.
- Usable Sensitivity (Mono, 30dB S/N, at 98.1MHz): 17.2dBf.
- -3dB Limiting Sensitivity (at 98.1MHz): 19.2dBf.
- Residual Noise (Ref. 400Hz, at 98.1MHz): 25±2dBf.
- S/N Ratio (Stereo, at 98.1MHz): 56dB.
- Image Rejection (at 106.1MHz): 40dB.
- IF Rejection (at 98.1MHz): 80dB.
- Distortion (Input 100dB µ, at 98.1MHz): 1%.
- Frequency Response (Ref. 400Hz): 100Hz: 0±3dB, 10kHz: -12±3dB.
- Stereo Separation (1kHz, at 98.1MHz): 20dB.
- PS Sensitivity (at 98.1MHz): 36.2dBf.
MW Radio Section:
- Intermediate Frequency: 450kHz.
- Frequency Range: 531~1,602kHz.
- Usable Sensitivity (20dB S/N, at 999kHz): 36dB.
- S/N Ratio (at 999kHz): 44dB.
- Image Rejection (at 1,404kHz): 50dB.
- IF Rejection (at 693kHz): 60dB.
- Distortion (at 999kHz): 1.5%.
- Frequency Response (Ref. 400Hz, at 999kHz): 100Hz: -3±4dB, 4kHz: -12±6, -12dB.
LW Radio Section:
- Intermediate Frequency: 450kHz.
- Frequency Range: 153~281kHz.
- Usable Sensitivity (20dB S/N, at 216kHz): 36dB.
- S/N Ratio (at 216kHz): 42dB.
- Distortion (at 216kHz): 1.5%.
- Frequency Response (Ref. 400Hz, at 216kHz): 100Hz: -3±4dB, 4kHz: -12±6, -12dB.
General Specifications:
- Power Supply: DC14.4V.
- Power Output (T.H.D. 10%) /Impedance: 14W/ch/4ohm.
- Pre Output/Impedance: 1.7V/10Kohm.
- Semiconductors: 28IC's, 52Transistors, 25Diodes, 14Zener Diodes.
- Dimensions (W×H×D): Chassis: 178×50×153mm, Nose: 170×46×18mm.
- Weight: 1.8kg.
Sensors Specification:
- Magazine Tray Motor (M LOAD 1/2): Motor used, Voltage Range 2.6V~7.0V, Rating 7.0V. Normal current 370mA Max, Starting current 930mA Max.
- Load Motor (D LOAD 1/2): Motor used, Voltage Range 2.6V~7.0V, Rating 7.0V. Normal current 370mA Max, Starting current 930mA Max.
- Magazine SW (M SW): Detects if magazine is inserted (Low: present, High: absent).
- Load SW (D LOAD SW): Detects if disc is in specified place or sent to drive unit (High -> Low: Up-edge detection).
- Photo 1 & 2: Detects presence/absence of disc during loading/unloading.
- Linear Position Sensor (LPS): Rate Voltage MAX 5V. Detects disc elevator, mechanism home, and eject positions. HEX codes and corresponding voltages are provided for each position (Eject, Home, Disc 1, Disc 2, Disc 3).
Usage Features:
The 3DE-7886R is designed for in-dash installation, providing a multi-CD playback solution. The user interacts with the unit through a control panel, which includes buttons for disc selection, source, and eject. The LPS ensures precise positioning of the disc tray for smooth operation. The system incorporates error handling mechanisms to address issues like LPS abnormality or disc loading/unloading failures, displaying an "ERROR" code when necessary. The unit can also enter a STAND BY MODE under specific conditions, such as ACC OFF or forced standby.
Maintenance Features:
The manual provides detailed disassembly and assembly instructions for various components, including the plate door, nose unit, front escutcheon, CD deck mechanism, main P.W.Board, mini P.W.Board, and front P.W.Board. Specific torque values are given for tightening screws to ensure proper assembly.
Key maintenance considerations include:
- Electrostatic discharge (ESD) precautions: When working on certain steps, an electrostatic band must be worn.
- FPC Pick-Up P.C.Board handling: Short-circuiting patterns before removal and careful handling are crucial to prevent damage to the Pick-Up Unit.
- Solder points: Specific solder points need to be removed and re-soldered during disassembly and assembly.
- Flexible patterns: Care must be taken not to damage flexible patterns by high temperature during soldering.
- LPS terminal: The terminal of the LPS (VR1101) should not be bent after removing the Switch P.C.Board.
- Lens handling: The lens of the Pick-Up Unit (HD1101) should not be touched.
- Connector tabs: Care must be taken not to damage the connector tabs of the Pick-Up Unit.
- Gear section: When removing the sled motor, care must be taken not to damage the gear section.
- Velcro tape: The velcro tape on the FPC Motor P.C.Board should be handled carefully to avoid damage.
- Timing chart and error handling: The manual outlines procedures for diagnosing and resolving operational errors based on the timing chart and error codes. This includes rechecking LPS values, applying reverse rotation for disc return/ejection failures, and positional correction disposal.
The manual also includes a comprehensive parts list with symbol numbers, part numbers, and descriptions for ICs, transistors, diodes, filters, surge protectors, switches, thermistors, buzzers, capacitors, coils, crystals, and resistors, facilitating component replacement and repair.
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