JVC SERVICE MANUAL

Contents

• Safety Precautions

• 1. Specifications

• 2. Names of Controls and Their Functions

• 3. Removal Procedures

  • 3-(1) Metal cover section

  • 3-(2) Front panel section

  • 3-(3) Chassis base section

• 4. FM/AM(MW/LW) Tuner Alignment Procedures

• 5. Block Diagram

• 6. RX-111BK/RX-111LBK Schematic Diagram

  • 6-(1) RX-111BK Tuner Section

  • 6-(2) RX-111LBK Tuner Section

  • 6-(3) RX-111BK/RX-111LBK Amplifier Section

  • 6-(4) Internal Block Diagram of Major LSI ICs

• Parts List

Safety Precautions

This product contains special hardware, many circuits, and components for safety purposes. For continued protection, no changes should be made to the original design unless authorized in writing by the manufacturer. Replacement parts must be identical to those used in the original circuits. Service should be performed by qualified personnel only.

Alterations of the design or circuitry should not be made. Any design alterations or additions will void the manufacturer's warranty and relieve the manufacturer of responsibility for personal injury or property damage.

Many electrical and mechanical parts have special safety-related characteristics that are often not evident from visual inspection. Replacement parts that have these special safety characteristics are identified in the parts list and by shading on schematics. Using substitute parts without these characteristics may create shock, fire, or other hazards.

Product leads are routed and dressed to separate them from live parts, high temperature parts, moving parts, and sharp edges to prevent electric shock and fire hazards. Original lead routing and dress should be observed during service.

When replacing the power cord or AC outlet, ensure the power switch or primary fuse is NOT connected to the ground power side of the plug and AC outlet.

Leakage Current Check (Safety for electrical shock hazard)

After re-assembly, perform an isolation check on exposed metal parts (antenna terminals, knobs, metal cabinet, screw heads, headphone jack, control shafts) to ensure safety. Do not use a line isolation transformer during this check.

Procedure:

1. Plug the AC line cord directly into the AC outlet.
2. Using a "Leakage Current Tester", measure the leakage current from each exposed metal part of the cabinet to a known good earth ground. Any leakage current must not exceed 0.5 mA AC (r.m.s.).

Alternate check method:

1. Plug the AC line cord directly into the AC outlet.
2. Use an AC voltmeter with 1,000 ohms per volt or more sensitivity.
3. Connect a 1500 Ω 10 W resistor paralleled by a 0.15 µF AC-type capacitor between an exposed metal part and a known good earth ground.
4. Measure the AC voltage across the resistor with the AC voltmeter.
5. Move the resistor connection to each exposed metal part, particularly those with a return path to the chassis, and measure the AC voltage. Reverse the plug in the AC outlet and repeat each measurement. Any voltage measured must not exceed 0.75 V AC (r.m.s.), which corresponds to 0.5 mA AC (r.m.s.).

Diagram Description: Diagram illustrating the procedure for checking leakage current. It shows an AC voltmeter connected to an exposed metal part of the product and a known good earth ground, with a resistor and capacitor in series between the product and ground.

Checking Line Voltage

Except for U.S.A., Canada, Australia, U.K. and Continental Europe: Before inserting the power plug, check and adjust the voltage selector switch to match the line voltage in your area. Disconnect the power plug before adjusting the switch.

1. Specifications

AMPLIFIER SECTION

FM TUNER SECTION

AM TUNER SECTION

LW (RX-111LBK only)

Design and specifications subject to change without notice.

Power Specifications

Dimensions and Weight

2. Names of Controls and Their Functions

Diagram Description: Diagram showing the front panel layout of the JVC RX-111BK stereo receiver, labeling controls such as POWER, STAND BY, TREBLE, BASS, SOURCE INDICATOR, PHONES, SPEAKERS, and display elements.

Front Panel Controls

1. POWER: Press to turn the power ON. Press STAND BY () to put the unit in standby mode. The memory circuit operates in STAND BY mode, maintaining preset stations and source selections even during power outages for up to a couple of days. Note: The unit consumes approximately 5 watts in STAND BY mode. Disconnect the power cord to shut off completely. An electronic source selector is used; ensure a source is selected after initial power-on.

2. TREBLE: Slide right to boost treble response, left to decrease.

3. BASS: Slide right to boost bass response, left to decrease.

4. Source Indicators: Lights up to indicate the selected source.

5. Frequency Display: Digitally displays the tuned frequency. For AM: four digits (kHz). For LW: three digits (kHz). For FM: five digits (MHz). For U.S.A./Canada: four digits (MHz).

6. TUNING UP/DOWN: Press to change frequency in steps. Continuous press scans at high speed, stopping when released. Tap lightly for precise tuning.

Channel Spacing: AM channel spacing knob (RX-111BK only) on the rear panel allows selection of 9 kHz or 10 kHz steps.

Note: *Preset at the factory.

Front Panel Controls (Continued)

7. SIGNAL indicator: Lights when a signal is input. Tune frequency while watching the display.

8. FM STEREO indicator: Lights when tuned to an FM stereo broadcast.

MEMORY indicator: Lights when the unit is ready to store a preset frequency. Goes out automatically after about 10 seconds or when a station select button is pressed.

MEMORY Button: Press to activate memory storage; indicator lights up. Press a station select button within 10 seconds to store the frequency.

FM MODE (MUTE): Selects FM AUTO (MUTE ON) or MONO (MUTE OFF). AUTO mode eliminates inter-station noise. MONO improves sound quality for weak signals or unsatisfactory stereo reception.

VOLUME: Knob with auto loudness effect, compensating high and low frequencies at lower volumes.

BALANCE: Adjusts balance between left and right speakers.

PHONES Jack: For private listening or monitoring.

SPEAKERS-1 / SPEAKERS-2 Buttons: Press to switch connected speakers on/off. Note: If only one speaker system is connected, press only its button. If both buttons are pressed, no sound will be heard.

10. TAPE MONITOR: Press to listen to the tape deck or the selected source.

11. CD/VIDEO SOUND: Press to hear or record sound from CD, video, or other connected equipment.

12. PHONO: Press to hear or record sound from a turntable.

13. FM Button: Selects FM tuner section.

14. AM (MW) Button: Selects AM (MW) tuner section. (LW for RX-111LBK only).

15. LW Button: Selects LW tuner section (RX-111LBK only).

16. Station select buttons: Used to select preset stations or store frequencies in memory. Press with MEMORY button to store.

PRESET SELECT Button: Selects channels 1-8 or 9-16 (for Continental Europe, U.K., Australia).

3. Removal Procedures

Diagram Description: Diagrams illustrating the disassembly steps for the JVC RX-111BK/RX-111LBK, showing the location of screws and fasteners for removing the metal cover, front panel, and chassis base.

3-(1) Metal Cover Section

1. Remove screws securing the metal cover (two from sides, three from the rear).
2. Extract the metal cover by lifting its rear side.

3-(2) Front Panel Section

1. Demount the metal cover (refer to 3-(1)).
2. Remove three screws (a, b, c).
3. Remove five screws (1 through 5) that secure the front panel and chassis base from the bottom side.
4. Remove screw (6) that secures the front panel through its lower side.

3-(3) Chassis Base Section

1. Demount the metal cover (refer to 3-(1)).
2. Remove 16 screws (1 through 5 and 7 through 17) that secure the chassis base from the bottom side.
3. Remove two screws (18 and 19) securing the heat sink.
4. Remove screw (20) securing the tuner PC board.
5. Extract the plastic rivet securing the amplifier PC board.
6. Remove four fasteners (A, B, C, and I) securing the tuner PC board and amplifier PC board. Grip fastener heads with pliers to remove.
7. Open the chassis base while loosening the stopper engaged with the rear panel.

4. FM/AM (MW/LW) Tuner Alignment Procedures

Diagram Description: Schematic diagram for FM/AM/LW tuner alignment procedures, indicating test points, adjustment components (coils, capacitors), and signal generator connections.

FM Section

Band Cover

1. Set frequency display to 108.0 MHz.
2. Connect a DC VTVM to TP401 and TP402 (GND).
3. Adjust L111 for 9.00 V on the VTVM.
4. Set frequency display to 87.5 MHz.
5. Check VTVM reading: 1.60 V ± 0.5 V.

Note: After adjustment, confirm band cover is as follows (for West Germany only): FM Low-end 87.5 MHz -300 kHz, High-end 108.0 MHz +500 kHz.

Sensitivity

Low Frequency

1. Connect an RF generator to 75 Ω antenna terminals via a dummy antenna.
2. Set RF generator to 90 MHz, 1 kHz modulation, 75 kHz deviation, input 1 µV.
3. Connect a VTVM and oscilloscope to Rec. out jacks.
4. Set frequency display to 90 MHz.
5. Adjust coils L101, L102 to maximize output.

High Frequency

1. Set RF generator to 106 MHz, 1 kHz modulation, 75 kHz deviation, input 1 µV.
2. Set frequency display to 106 MHz.
3. Adjust FM trimmers C101, C104 to maximize output.
4. Repeat high and low frequency adjustments alternately until maximum sensitivity is obtained.

Discriminator, Distortion and Signal Gain

1. Set to FM position.
2. Connect RF generator (1 kHz modulation, 75 kHz deviation) to antenna terminals via dummy antenna.
3. Connect oscilloscope, Distortion Meter, and VTVM to Rec. out jacks.
4. Set RF generator to 98 MHz, minimize output.
5. Set frequency display to 98 MHz.
6. Connect DC VTVM between TP141 and TP142.
7. Set RF generator output to 0.5 mV.
8. Adjust core of T141 for DC VTVM reading of 0 (zero) mV.

Stereo Separation (for Europe, U.K. and Australia only)

1. Set stereo signal generator: 400 Hz modulation, 7.5 kHz deviation pilot, 67.5 kHz main and sub carriers. Connect output to RF generator.
2. Connect RF generator to antenna terminals via dummy antenna.
3. Switch stereo modulator to left channel modulation.
4. Adjust R172 to minimize right channel output.
5. Switch modulator to right channel modulation.
6. Adjust R172 to minimize left channel output.
7. Set R172 to an average if separation is uneven.

AM (MW) Section

Band Cover

1. Press AM (MW) position.
2. Set frequency display to 520 kHz (10 kHz step) or 522 kHz (9 kHz step).
3. Connect DC VTVM to TP401 and TP402 (GND).
4. Adjust L222 for 0.95 V on VTVM.
5. Set frequency display to 1710 kHz (10 kHz step) or 1611 kHz (9 kHz step).
6. Adjust C225 for 9.00 V (1710 kHz) or 7.50 V (1611 kHz) on VTVM.

Tracking and Sensitivity

Note: Perform this adjustment after LW tracking adjustment.

1. Connect loop antenna. Connect RF generator to antenna terminal via rear panel.
2. Set generator to 600 kHz (or 603 kHz) with 30% modulation at 400 Hz.
3. Set frequency display to 600 kHz (or 603 kHz).
4. Adjust L221 core for maximum output.
5. Set generator to 1400 kHz (or 1404 kHz).
6. Set frequency display to 1400 kHz (or 1404 kHz).
7. Adjust C222 for maximum output signal.
8. Repeat steps 1-7 alternately until maximum sensitivity is obtained.

LW Section

Band Cover

1. Press LW position.
2. Set frequency display to 153 kHz.
3. Connect DC VTVM to TP401 and TP402 (GND).
4. Adjust L202 for 1.10 V on VTVM.
5. Set frequency display to 360 kHz.
6. Adjust C205 for 8.00 V on VTVM.

Tracking and Sensitivity

1. Connect loop antenna. Connect RF generator to antenna terminal via rear panel.
2. Set generator to 164 kHz with 30% modulation at 400 Hz.
3. Set frequency display to 164 kHz.
4. Adjust L201 core for maximum output.
5. Set generator to 353 kHz.
6. Set frequency display to 353 kHz.
7. Adjust C202 for maximum output signal.
8. Repeat steps 1-7 alternately until maximum sensitivity is obtained.

5. Block Diagram

Diagram Description: Block diagram of the JVC RX-111BK/RX-111LBK stereo receiver, illustrating the signal flow from the antenna through various stages including RF amplification, tuning, detection, multiplexing, synthesis, control, display, power supply, and audio amplification.

The block diagram outlines the main functional units of the receiver. The signal path begins at the ANTENNA input, which connects to FM, AM, and LW RF amplifier stages. These signals are then mixed and processed through IF amplifiers and detectors. The FM signal is further processed by a multiplex (MPX) section for stereo reception. A PLL synthesizer, controlled by the TUNER CONTROL SWITCH and IC401 (TC9147BP), manages tuning across FM, AM, and LW bands. The frequency display is driven by FL DRIVE and IC441 (TC9158P). Source selection is handled by SOURCE SELECT SWITCH (SW301-303), feeding signals to an EQ. AMP (IC301) for PHONO and a CD/VIDEO SOUND input. TAPE MONITOR and TAPE REC/PLAY functions are also managed. The audio signal is processed through VOLUME and TONE CONTROL circuits before reaching the POWER AMP (IC701 STK4141II). A MUTING circuit and SPEAKER SWITCHes are also included. The power supply provides various voltage rails (+5V, +11V, -9V, -26V) to the different sections.

6. RX-111BK/RX-111LBK Schematic Diagram

Detailed schematic diagrams for the RX-111BK/RX-111LBK tuner and amplifier sections, showing internal circuitry, component interconnections, and integrated circuits. These diagrams are crucial for service technicians.

6-(1) RX-111BK Tuner Section

This section details the circuitry for the tuner, including RF amplification, mixing, IF processing, and detection for FM, AM, and LW bands. It shows specific components like transistors (Q101, Q102, etc.), ICs (IC141, IC171), coils (L101, L102, etc.), capacitors (C101, C104, etc.), and switches used in the tuning and reception process.

6-(2) RX-111LBK Tuner Section

Similar to the RX-111BK tuner section, this schematic illustrates the tuner circuitry, potentially with minor variations specific to the RX-111LBK model's LW reception capabilities or component choices.

6-(3) RX-111BK/RX-111LBK Amplifier Section

This schematic covers the audio amplifier circuitry, including pre-amplification, tone control, volume control, muting, and the main power amplifier stage (IC701 STK4141II). It details the components and connections required for audio signal processing and output to the speakers.

6-(4) Internal Block Diagram of Major LSI ICs

This section provides internal block diagrams for key Integrated Circuits (ICs) used in the receiver, such as TC9147BP (PLL Synthesizer), AN7223 (FM IF Amp, Detector, etc.), LA3410 (AM RF Amp, Mixer, Detector), and TD6104P (Display Driver). These diagrams illustrate the internal logic and functions of these complex chips.

Parts List

The following sections list the components used in the JVC RX-111BK/RX-111LBK stereo receiver. These lists are essential for identifying and sourcing replacement parts.

Transistors

ICs

Diodes

Capacitors

Resistors

Main Parts Locations

Diagram Description: Diagrams showing the front, top, and rear views of the JVC RX-111BK/RX-111LBK stereo receiver, indicating the location of major components and assemblies.

1-(1) Front View

Shows the front panel with controls like knobs, switches, display, and jacks. Key parts identified include Metal Cover (E24633-003), Push Knob (E72355-001), Jack Assy (QMS6302-128), Push Switch (QST8261-E02), Slide Knob (E72113-001), and Push Knob (E71268-002).

1-(2) Top View

Illustrates the internal layout. Key parts include Audio P.C. Board Assy (ENH-055), Power Transformer (ETP1070-16), Push Switch (QSP2206-001), and Tuner P.C. Board Assy (ENA-038).

1-(3) Rear View

Shows the rear panel connections. Key parts include Antenna Terminal (EMB01YV-201A), GND. Terminal (E70078-001), Window Screen (E303676-005), Rear Panel (E302334-001), Speaker Terminal (EMB90TV-801A), and Power Cord.

2. Exploded View and Part Numbers

Diagram Description: An exploded view diagram of the JVC RX-111BK/RX-111LBK stereo receiver, showing how various parts fit together and listing their corresponding part numbers and areas of use.

This section provides a detailed breakdown of the unit's assembly, with diagrams and corresponding part numbers for each component, including front panel parts, chassis base, rear panel, and internal assemblies.

3. Printed Circuit Board Ass'y and Parts List

This section details the Printed Circuit Boards (PCBs) used in the receiver and their associated parts. It lists different PCB assemblies (ENA-038 for Tuner, ENH-055 for Audio) and their designated areas of use.

4. Packing Materials and Part Numbers

Lists the packing materials used for the product, such as envelopes, packing pads, and packing cases, along with their part numbers and designated areas.

5. Accessories List

Lists the accessories included with the receiver, such as Instruction Books, Warranty Cards, Service Information Cards, fuses, antennas, and plugs, along with their part numbers and designated areas.