Yamaha TX-396-L Service manual

TX-396L

P.O.Box 1, Hamamatsu, Japan

AM/FM STEREO TUNER

TX-396L

SERVICE MANUAL

IMPORTANT NOTICE

This manual has been provided for the use of authorized YAMAHA Retailers and their service personnel. It has been assumed that basic service procedures inherent to the industry, and more specifically YAMAHA Products, are already known and understood by the users, and have therefore not been restated.

WARNING: Failure to follow appropriate service and safety

procedures when servicing this product may result in personal injury, destruction of expensive components, and failure of the product to perform as specified. For these reasons, we advise all YAMAHA product owners that any service required should be performed by an authorized YAMAHA Retailer or the appointed service representative.

IMPORTANT: The presentation or sale of this manual to any individual

or firm does not constitute authorization, certification or recognition of any applicable technical capabilities, or establish a principle-agent relationship of any form.

■ CONTENTS

TO SERVICE PERSONNEL .......................................... 1

SPECIFICATIONS .......................................................... 1

INTERNAL VIEW ........................................................... 2

REAR PANELS .............................................................. 2

DISASSEMBLY PROCEDURES ................................... 2

ADJUSTMENTS ......................................................... 3~7

The data provided is believed to be accurate and applicable to the unit(s) indicated on the cover. The research, engineering, and service departments of YAMAHA are continually striving to improve YAMAHA products. Modifications are, therefore, inevitable and specifications are subject to change without notice or obligation to retrofit. Should any discrepancy appear to exist, please contact the distributor's Service Division.

WARNING: Static discharges can destroy expensive components.

Discharge any static electricity your body may have accumulated by grounding yourself to the ground buss in the unit (heavy gauge black wires connect to this buss).

IMPORTANT: Turn the unit OFF during disassembly and part

replacement. Recheck all work before you apply power to the unit.

µCOM DATA .................................................................. 8

DISPLAY DATA ............................................................. 9

BLOCK DIAGRAM ................................................. 10~11

PRINTED CIRCUIT BOARD .................................. 12~13

SCHEMATIC DIAGRAM ........................................ 14~15

PARTS LIST ........................................................... 16~21

100700

TX-396L

WALL

OUTLET

EQUIPMENT

UNDER TEST

AC LEAKAGE

TESTER OR

EQUIVALENT

INSULATING

TABLE

■ TO SERVICE PERSONNEL

Critical Components Information. Components having special characteristics are marked and must be replaced with parts having specifications equal to those originally installed.

WARNING: CHEMICAL CONTENT NOTICE!

The solder used in the production of this product contains LEAD. In addition, other electrical/electronic and /or plastic (where applicable) components may also contain traces of chemicals found by the California Health and Welfare Agency (and possibly other entities) to cause cancer and/or birth defects or other reproductive harm.

DO NOT PLACE SOLDER, ELECTRICAL/ELECTRONIC OR PLASTIC COMPONENTS IN YOUR MOUTH FOR ANY REASON WHATSOEVER!

Avoid prolonged, unprotected contact between solder and your skin! When soldering, do not inhale solder fumes or expose eyes to solder/flux vapor!

If you come in contact with solder or components located inside the enclosure of this product, wash your hands before handling food.

■ SPECIFICATIONS

■ FM SECTION

Tuning Range 87.50 to 108.00 MHz 50dB Quieting Sensitivity (IHF)

Mono 1.55 µV(15.1 dBf) Stereo (1 kHz 100% MOD) 21 µV(37.7 dBf)

Usable Sensitivity (DIN)

Mono (S/N 26 dB) 0.9 µV Stereo (S/N 46 dB) 24 µV

Alternate Channel Selectivity

Selectivity (two signals) 40 kHz Dev. ±300 kHz 70 dB

Signal to Noise Ratio (DIN-Weighted 40 kHz)

Mono 75 dB Stereo 70 dB

Harmonic Distortion 1 kHz

Mono 0.1 % Stereo 0.2 %

Stereo Separetion 1kHz (40 kHz Dev.) 50 dB Frequency Response

20 Hz to 15 kHz 0±0.5 dB

■ MW SECTION Tuning Range 531 to 1611 kHz Usable Sensitivity 200 µV/m Signal to Noise Ratio 50 dB Harmonic Distortion 1 kHz 0.3 %

■ LW SECTION Tuning Range 153 to 288 kHz Usable Sensitivity 400 µV/m Signal to Noise Ratio 50 dB Harmonic Distortion 1 kHz 0.3 %

■ AUDIO SECTION Output Level/Impedance (Fixed)

FM 100 % MOD 1 kHz 500 mV/2.2 kΩ MW/LW 30 % MOD 1 kHz 200 mV/2.2 kΩ

■ GENERAL Power Supply AC230V, 50Hz Power Consumption 7 W Dimensions (W x H x D) 435 x 86 x 278mm Weight 3.2 kg

* Specifications subject to change without notice.

• MODEL COLOR

Black and Gold

• DIMENSIONS

27886

263.5 11.33.27016

435

34 5 6

■ INTERNAL VIEW

TX-396L

■ REAR PANEL

1 Tuner P. C. B (1) 2 Front-end pack 3 Operation P. C. B. (2) 4 Tuner P. C. B. (2) 5 Operation P. C. B. (1) 6 Operation P. C. B. (3)

■ DISASSEMBLY PROCEDURES

(Remove parts in the order as numbered.)

1. Removal of Top Cover

Remove 4 screws (1) and 2 screws (2) in Fig. 1.

2. Removal of Front Panel

a. Disconnect the connectors (CB3 anf CB4) in Fig. 1. b. Remove 2 plastic rivets (3) in Fig. 1. c. Remove 5 screws (4) in Fig. 1. d. Unhook at 2 place (5) in Fig. 1.

TX-396L

FM SG

Oscilloscope

ACVM

DIST. M

ANT

OUT PUT

GND

dummy

antenna

Tuner

P. C. B.

FM SG

Oscilloscope

ACVM

DIST. M

ANT

YLF-15

(LPF)

OUT PUT

GND

dummy

antenna

Tuner

P. C. B.

SSG

FM SG

Oscilloscope

ACVM

DIST. M

ANT

OUT PUT

GND

dummy

antenna

Tuner

P. C. B.

oscillator

FM SG

DCVM

ANT

TP1

TP2

R51

GND

dummy

antenna

Tuner

P. C. B.

oscillator

■ ADJUSTMENTS

1. Before Adjustment

(1)With the power turned on, wait for 5 minutes before

starting adjustment so that operation becomes stable. (2)Adjust the OSC coil and IFT with insulated screwdriver. (3)Set the TUNING MODE to AUTO. (4)Decibel abbreviations

dBµ : Decibels above or below 1µV Example :

0dBµ = 1 µv, 60dBµ = 1 mV

X dBµ = (X + 11.2) dBf

When substituting 60 for X,

60 dBµ = 72.2 dBf

2. Measuring instrument abbreviations

FM SG : FM signal generator

SSG : Stereo signal generator

AM SG : AM signal generator

DIST. M : Distortion meter

FC : Frequency counter

ACVM : AC voltage meter

DCVM : DC voltage meter

(1)All the segments on the display light up. (2)The model name, TX-396L is displayed. (3)The place of destination is displayed. (4)The µCOM-version is displayed.

Pressing the P1 key will cause operation to start from (1). Pressing any other key will cause the mode to return to the NORMAL mode.

Preset

A, E 87.50 90.10 95.10 98.10 108.00 88.10 106.10 108.00

B, D 630 1080 1440 531 1611 900 1350 1404

P1 P2 P3 P4 P5 P6 P7 P8

C 153 171 225 270 288 180 207 252

1) Discriminator balance adjustment

Check that the voltage obtained across each test point and ground on the tuner circuit is as follows.

Test points Rating or Standard

+5 V terminal +5.6 ±0.5 V

-VP terminal -23.0 ±1.0 V

CAUTION :

Before setting to the TEST mode, write down the user preset memory content in the table as shown below. (This is because setting to the TEST mode will cause the memory content to be the factory preset memory content, i.e. all the user preset memory content will be erased.)

Preset keys

P1 P2 P3 P4 P5 P6 P7 P8

2) Monaural distortion adjustment

3) Stereo distortion adjustment

4) Sensitivity verification

• Turn on the POWER switch while pressing the A/B/C/D/

E and FM/AM(FM/MW/LW) keys simultaneously, and

the unit enters the TEST mode for the display check.

After this, repeat (1) to (4).

D

● TEST POINTS

DISCRIMINATOR

BALANCE

TP2

PK2

STEREO

DISTORTION

PK1

LINEOUT AMANT GND FMANT

MONAURAL

DISTORTION

TP1

L13 L12 VR4

L10

R51

SEPARATION

TX-396L

Step

Adjustment item

Rough adjustment of discriminator balance.

Rough adjustment of

monaural distortion.

SIGNAL

VR3

METER

Signal (ANT IN)

FM SG:

98.1 MHz 70 dBµ Modulation : 100 % Monaural : 1 kHz

Same as Step 1.

VR2

AMSENSITIVITY

TP3

J73

Reception frequency

Preset A-4: 98.1 MHz

Same as Step 1.

VR1

Adjusted

point

L8 (right side)

L8 (left side)

Test point

TP1, TP2 (both end of R51)

OUTPUT

FRONTEN IFT

Rating

DC 0 V ±100mV at tuning point.

Minimize distortion.

Fine adjustment of

discriminator balance.

Fine adjustment of

monaural distortion.

Verification of

discriminator balance.

Adjustment of frontend IFT.

Adjustment of stereo distortion.

Same as Step 1.

FM SG:

98.1 MHz 30 dBµ Modulation : 100 % Monaural : 1 kHz

FM SG:

98.1 MHz 70 dBµ Modulation : 100 % Stereo L or R : 1 kHz

Same as Step 1.

L8 (right side)

L8 (left side)

Frontend IFT

VR1, VR2

TP1, TP2

OUTPUT

TP1, TP2

TP3, GND

OUTPUT

DC 0 V ±50mV

Minimize distortion. (to less than 0.7%)

DC 0 V ±50mV

Adjust so that the DC voltage is maximum.

CAUTION:

If IFT core is turned excessively, the sensitivity reduces. (Maximum ±90°)

Minimize distortion. Tuning mode is AUTO.

TX-396L

Step

Adjustment item

Verification of monaural distortion.

Verification of stereo distortion.

Verification of sensitivity.

Adjustment of separation.

Signal (ANT IN)

FM SG:

98.1 MHz 70 dBµ Modulation : 100 % Monaural : 1 kHz

FM SG:

98.1 MHz 70 dBµ Modulation : 100 % Stereo L or R : 1 kHz

FM SG:

88.1/98.1/106.1 MHz Modulation : 100 % Monaural : 1 kHz

FM SG:

98.1 MHz 70 dBµ Modulation : 100 % Stereo L or R : 1 kHz

Reception frequency

Same as Step 1.

A-6: 88.1 MHz A-4: 98.1 MHz A-7: 106.1 MHz

Preset A-4: 98.1 MHz

Adjusted

point

VR4

Test point

OUTPUT

Rating

Minimize distortion. (to less than 0.7%)

Minimize distortion. (to less than 1.4%) Tuning mode is AUTO.

S/N should be 30 dB at each frequency of

88.1 MHz, 98.1 MHz and 106.1 MHz. Make sure that the voltage at the ANT terminal is 7 dBµ or less.

To more than 35 dB. Tuning mode is AUTO.

Adjustment of the signal meter.

Verification of the signal meter to turn off.

Verification of AUTO TUNING.

FM SG:

98.1 MHz 45 dBµ Modulation : 30 % Monaural : 1 kHz

ANT input minimum.

FM SG:

98.1 MHz 23 dBµ Modulation : 30 % Stereo L or R : 1 kHz

Preset A-4: 98.1 MHz

VR3

Tuning buttons

Signal meter

Adjust so that the signal meter is maximum at rating level.

Make sure that the signal meter is turned off.

Automatic reception should be available when the tuning UP or DOWN key is pressed. Stereo indicator is turned on. Audio muting should be applied during tuning.

+ 14 hidden pages

Yamaha TX-396-L Service manual

Specifications and Main Features

Frequently Asked Questions

User Manual

■ CONTENTS

■ TO SERVICE PERSONNEL

■ SPECIFICATIONS

■ INTERNAL VIEW

■ REAR PANEL

■ DISASSEMBLY PROCEDURES

■ ADJUSTMENTS

● TEST POINTS