Yamaha TX-497 User manual

SERVICE MANUAL
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.
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.
IMPORTANT NOTICE
100970
SERVICE MANUAL
BLOCK DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . .19
PRINTED CIRCUIT BOARD . . . . . . . . . . . . . . . . . . .20
SCHEMATIC DIAGRAM . . . . . . . . . . . . . . . . . . .21–22
PARTS LIST . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23–31
■ CONTENTS
TO SERVICE PERSONNEL . . . . . . . . . . . . . . . . . . . .2
SPECIFICATIONS / . . . . . . . . . . . . . . . . . . . .3
FRONT PANELS . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
REAR PANELS . . . . . . . . . . . . . . . . . . . . . . . . . . . .4–5
INTERNAL VIEW . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6
DISASSEMBLY PROCEDURES / . . . . . . . .6
ADJUSTMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . .7–11
12–15
IC DATA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
DISPLAY DATA . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17
AM/FM STEREO TUNER
TX-497
TX-497
2005 . All rights reserved.
This manual is copyrighted by YAMAHA and may not be copied or
redistributed either in print or electronically without permission.
05.09

2
TX-497
TX-497
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 REA-
SON 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.
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.
WALL
OUTLET EQUIPMENT UNDER TEST
AC LEAKAGE
TESTER OR
EQUIVALENT
INSULATING
TABLE
About leadfree solder / 無鉛ハンダについて
The P.C.B.s installed in this unit are soldered using the
following solder.  





注意：
󰴤


󰴥



Among some types of lead free solder currently available,
it is recommended to use one of the following types for the
repair work.
Sn + Ag + Cu (tin + silver + copper)
Sn + Cu (tin + copper)
Sn + Zn + Bi (tin + zinc + bismuth)
Caution:
1. As the melting point temperature of the lead free solder
is about 30°C to 40°C (50°F to 70°F) higher than that of
the lead solder, be sure to use a soldering iron suitable
to each solder.
2. If lead solder must be used, be sure to remove lead free
solder from each terminal section of the parts to be
replaced and from the area around it completely before
soldering, or make sure that the lead-free solder and
lead solder melt together fully.
TUNER P.C.B.
OPERATION P.C.B.
Side A / 
—
—
Side B / 
Lead Free Solder / 
Lead Free Solder / 
Side A
Side B
SMT REFLOW Process
MI FLOW Process
Solder Dip

3
TX-497
TX-497
FM SECTION /FM 部
Tuning Range / 受信周波数範囲
U, C models ..................................... 87.5 to 107.9 MHz
R, T, A, B, G, E, L models ............ 87.50 to 108.00 MHz
J model .............................................. 76.0 to 90.0 MHz
50dB Quieting Sensitivity /50dBSN
感度 (IHF)
U, C, R, T,A, L, J models
Mono ................................................. 1.55 µV(15.1 dBf)
Stereo (1 kHz 100% MOD) 21 µV(37.7 dBf)
Usable Sensitivity /
実用感度 (DIN)
B, G, E models
Mono (S/N 26 dB) ............................................... 0.9 µV
Stereo (S/N 46 dB) .............................................. 24 µV
Image Response Ratio /
イメージ妨害比
U, C, R, T, J models ............................................. 40 dB
A, B, G, E, L models ............................................ 80 dB
IF Response Ratio /IF
妨害比 ..................................70 dB
Spurious Response Ratio /
スプリアス妨害比
U, C, R, T, J models ............................................. 60 dB
A, B, G, E, L models ............................................ 70 dB
Alternate Channel Selectivity /
実行選択度
U, C, R, T, J models ............................................. 85 dB
A, B, G, E, L models
Selectivity (two signals) 40 kHz Dev. ±300 kHz ... 70 dB
Signal to Noise Ratio /
信号対雑音比 (DIN-Weighted 40 kHz)
U, C, R, T, J models
Mono ....................................................................82 dB
Stereo .................................................................. 76 dB
A, B, G, E, L models
Mono ....................................................................75 dB
Stereo .................................................................. 70 dB
Harmonic Distortion /
歪率 (1 kHz)
Mono .................................................................... 0.1 %
Stereo (B, G: 40 kHz Dev.) ...................................0.2 %
Stereo Separation /
ステレオセパレーション (1 kHz)
B, G: 40 kHz Dev. ................................................ 50 dB
Frequency Response /
周波数特性
30 Hz to 13 kHz .............................................. 0±0.5 dB
MW SECTION /AM
部
Tuning Range / 受信周波数範囲
U, C, R models ....................................530 to 1710 kHz
T, A, B, G, E, L, J models .................... 531 to 1611 kHz
Usable Sensitivity /
実用感度 ............................ 200 µV/m
Selectivity /
選択度 ..................................................  32 dB
Signal to Noise Ratio /
信号対雑音比 ...................... 50 dB
Image Response Ratio /
イメージ妨害比 ................ 40 dB
Spurious Response Ratio /
スプリアス妨害比 .......  50 dB
Harmanic Distortion /
歪率 .....................................  0.3%
LW SECTION
Tuning Range
B, G, E models ......................................153 to 288 kHz
Usable Sensitivity
B, G, E models .............................................. 400 µV/m
Selectivity
B, G, E models .................................................... 32 dB
Signal to Noise Ratio
B, G, E models .....................................................50 dB
Image Response Ratio
B, G, E models .....................................................40 dB
Spurious Response Ratio
B, G, E models .....................................................50 dB
Harmanic Distortion
B, G, E models .....................................................0.3 %
AUDIO SECTION /
オーディオ部
Output Level / Impedance
（
出力電圧 / インピーダンス） (Fixed)
U, C, R, T, A, L, J models
FM 100 % MOD 1 kHz ................... 900 mV/2.2 k-ohms
MW/AM/LW 30 % MOD 1 kHz ........150 mV/2.2 k-ohms
B, G, E models
FM 100 % MOD 1 kHz ................... 500 mV/2.2 k-ohms
MW/LW 30 % MOD 1 kHz ..............200 mV/2.2 k-ohms
GENERAL /
総合
Power Supply / 電源電圧
U, C models ........................................... AC120V, 60Hz
R, L models ....... AC110 to 120V, 220 to 240V, 50/60Hz
T model ..................................................AC220V, 50Hz
A model ..................................................AC240V, 50Hz
B, G, E models .......................................AC230V, 50Hz
J model ............................................. AC100V, 50/60Hz
Power Consumption /
消費電力 .................................7 W

Dimensions / 寸法 (W x H x D) ........... 435 x 86 x 271mm
Weight /
質量 ........................................................... 3.2 kg
Finish /
仕上げ
Gold color ................................................T, L, J models
Black color ...................... U, C, R, A, B, G, L, E models
Titanium color ............................... R, B, G, L, E models
Accessories /
付属品
Indoor FM Antenna x 1
AM Loop Antenna x 1
Antenna Adapter x 1 (U, C models)
75-ohm/300-ohm antenna adapter x 1 (B model)
Audio Pin Cable
256.6
(10-1/8")
13.4 (1/2")
70
(2-3/4")
16
(5/8") 271
(10-11/16")
86
(3-3/8")
435
(17-1/18")
• DIMENSIONS
SPECIFICATIONS /参考仕様
* Specifications subject to change without notice.

4
TX-497
TX-497
FRONT PANELS
U, C, R, T, A, L, J models
B, G, E models
U, C models
R, L models
REAR PANELS

5
TX-497
TX-497
A model
B, G, E models
J model
T model

6
TX-497
TX-497
DISASSEMBLY PROCEDURES /
(Remove parts in the order as numbered.)
1. Removal of Top Cover
2. Removal of Front Panel Unit
a. Disconnect the connectors (CB3 and CB4). (Fig. 1.)
b. Remove 3 screws ( ). (Fig. 1.)
. Screws ( ) are identified with arrow marks ( ).
c. Remove 2 screws ( ). (Fig. 1.)
a. Remove 4 screws ( ) and 2 screws ( ). (Fig. 1.)
b. Slide the Top Cover rearward to remove it. (Fig. 1.)
e. Remove the Front Panel Unit. (Fig. 1.)
d. Unhook at 2 place ( ). (Fig. 1.)
INTERNAL VIEW
Tuner P. C. B
Front-end pack
Operation P. C. B. (2)
Operation P. C. B. (3)
Operation P. C. B. (1)
Operation P. C. B. (4) (R, L models)
r
e
r
t
t



 
 

 
 
  
 

 
 
分解手順





7
TX-497
TX-497
FM
SG
Oscilloscope
ACVM
DIST. M
FM
ANT L
R
OUT
PUT
GND
FM
dummy
antenna Tuner
P. C. B.
FM
SG
Oscilloscope
ACVM
DIST. M
FM
ANT L
RYLF-15
(LPF)
OUT
PUT
GND
FM
dummy
antenna Tuner
P. C. B.
SSG
FM
SG
Oscilloscope
ACVM
DIST. M
FM
ANT L
R
OUT
PUT
GND
FM
dummy
antenna Tuner
P. C. B.
oscillator
FM
SG DCVM
FM
ANT TP1
TP2
R51
GND
FM
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
RDS SG : RDS signal generator
<POWER SUPPLY CHECK>
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.)
<User preset memory content>
Preset keys P1 P2 P3 P4 P5 P6 P7 P8
A
B
C
D
E
<TEST mode>
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).
(1)All the segments on the display light up.
(2)The model name, TX-497 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.
B, G, E models
<Factory preset memory content>
Preset P1 P2 P3 P4 P5 P6 P7 P8
A, E 87.50 90.10 95.10 98.10 108.00 88.10 106.10 108.00
B, D 630 1080 1440 531 1711 900 1350 1400
C 153 171 225 270 288 180 207 252
<Connection Diagram (Measuring Instruments)>
1) Discriminator balance adjustment
2) Monaural distortion adjustment
3) Stereo distortion adjustment
4) Sensitivity verification
A, L, R models
Preset P1 P2 P3 P4 P5 P6 P7 P8
A, C, 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
U, C models
Preset P1 P2 P3 P4 P5 P6 P7 P8
A, C, E 87.5 90.1 95.1 98.1 107.9 88.1 106.1 107.9
B, D 630 1080 1440 530 1710 900 1350 1400

8
TX-497
TX-497
TEST POINTS
<FM TUNER SECTION>
Adjustment item
Rough adjustment of
discriminator balance.
Rough adjustment of
monaural distortion.
Fine adjustment of
discriminator balance.
Fine adjustment of
monaural distortion.
Verification of
discriminator balance.
Adjustment of frontend
IFT.
Adjustment of stereo
distortion.
Step
1
2
3
4
5
6
7
Signal (ANT IN)
FM SG:
98.1 MHz 70 dBµ
Modulation : 100 %
Monaural : 1 kHz
Same as Step 1.
Same as Step 1.
Same as Step 1.
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
Adjusted
point
L8
(right side)
L8
(left side)
L8
(right side)
L8
(left side)
Frontend
IFT
VR1, VR2
Reception
frequency
Preset
A-4: 98.1 MHz
Same as Step 1.
Same as Step 1.
Same as Step 1.
Same as Step 1.
Same as Step 1.
Same as Step 1.
Rating
DC 0 V ±100mV
at tuning point.
Minimize distortion.
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.
Test point
TP1, TP2
(both end
of R51)
OUTPUT
TP1, TP2
OUTPUT
TP1, TP2
TP3, GND
OUTPUT
   

  












TP2
TP1
TP3

GND
BALANCE
DISCRIMINATOR
DISTORTION
MONAURAL
FRONTEND
IFT
DISTORTION
STEREO
AMSENSITIVITY
SEPARATION
METER
SIGNAL

9
TX-497
TX-497
Adjustment item
Verification of monaural
distortion.
Verification of stereo
distortion.
Verification of
sensitivity.
Adjustment of
separation.
Adjustment of the signal
meter.
Verification of the signal
meter to turn off.
Verification of AUTO
TUNING.
Ste
8
9
10
11
12
13
14
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
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
Adjusted
point
VR4
VR3
Tuning
buttons
Reception
frequency
Same as Step 1.
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
Preset
A-4: 98.1 MHz
Preset
A-4: 98.1 MHz
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 3 dBµ(7
dBµat A, B, G, E
models) or less.
To more than 35 dB.
Tuning mode is
AUTO.
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.
Verification of AUTO PS
(program service name)
[B, G, E models only]
15
RDS SG:
Modulation : 1.6 %
(1.2 kHz)
FM SG:
98.1 MHz 40 dBµ
Modulation : 100 %
Monaural : 1 kHz
Preset
A-4: 98.1 MHz Make sure that the
display automatically
turns to the PS
mode and PS
indicator turns on
when the signal is
tuned again.
Test point
OUTPUT
OUTPUT
OUTPUT
Signal
meter

10
TX-497
TX-497
<MWTUNER SECTION>
To be adjusted after FM section adjustment.
Use the specified dummy anetenna for loop antenna.
Adjustment item
Adjustment of
sensitivity.
Verification of
sensitivity.
Verification of the signal
meter.
Verification of auto
tuning.
Step
1
2
3
4
Signal (ANT IN)
AM SG:
630 kHz 50 dBµ,
1 kHz,
30% modulation
AM SG:
630 kHz/1080 kHz/
1440 kHz 50 dBµ,
1 kHz,
30% modulation
AM SG:
1080 kHz 90 dBµ,
ANT input 90 dBµ
ANT input -10 dBµor
less
AM SG:
1080 kHz 60 dBµ,
1 kHz,
30% modulation
Adjusted
point
L5
Tuning
button
Reception
frequency
Preset
B-1: 630 kHz
Preset
B-1: 630 kHz
B-2: 1080 kHz
B-3: 1440 kHz
Preset
B-2: 1080 kHz
Preset
B-2: 1080 kHz
Rating
Maximize detected
signal output.
To be less than 54
dBµ.
Make sure that the
signal meter is
turned on.
Make sure that the
signal meter is
turned off.
Automatic reception
should be available
when the tuning UP
or DOWN key is
pressed.
Audio muting should
be applied during
tuning.
Test point
OUTPUT
AM
SG
AM ANT
GND
AM dummy antenna
AM loop antenna

11
TX-497
TX-497
Adjustment item
Verification of
sensitivity.
Verification of the signal
meter.
Verification of auto
tuning.
Step
1
2
3
Signal (ANT IN)
AM SG:
171 kHz/225 kHz/270
kHz 90 dBµ,
1 kHz,
30% modulation
AM SG:
225 kHz 90 dBµ,
ANT input 90 dBµ
ANT input -10 dBµor
less
AM SG:
225 kHz 60 dBµ,
1 kHz,
30% modulation
Adjusted
point
Tuning
button
Reception
frequency
Preset
C-2: 171 kHz
C-3: 225 kHz
C-4: 270 kHz
Preset
B-2: 225 kHz
Preset
B-2: 225 kHz
Rating
To be less than 66
dBµ.
Make sure that the
signal meter is
turned on.
Make sure that the
signal meter is
turned off.
Automatic reception
should be available
when the tuning UP
or DOWN key is
pressed.
Audio muting should
be applied during
tuning.
Test point
OUTPUT
<LW TUNER SECTION>
To be adjusted after MW section adjustment.
Use the specified dummy anetenna for loop antenna.
AM
SG
AM ANT
GND
AM dummy antenna
AM loop antenna

12
TX-497
TX-497
調整

13
TX-497
TX-497

14
TX-497
TX-497

15
TX-497
TX-497

16
TX-497
TX-497
IC DATA
IC501 : LC866420A
8-bit Microprocessor
No. Port I/O Name Function
1 P17/PWM0 O /MMUTE Main mute
2 P30 I ROT1 Rotary encoder input
3 P31 I ROT0 This input available for ROTSW=H
4 P32 I MODEL Model 0
5 P33 I ROTSW Rotary encoder yes(H) or no(L)
6 P70/INT0 I
7 /RES I /RESET Reset
8 /P74/XT1 I
9 P75/XT2 I
10 VSS1 I GND GND
11 CF1 CF 6MHz
12 CF2 CF 6MHz
13 VDD1 I VDD +5V
14 P80/AN0 ADI KEYIN1 AD key input
15 P81/AN1 ADI KEYIN2 AD key input
16 P82/AN3 ADI KEYIN3 AD key input
17 P83/AN3 ADI METER Signal level input
18 P84/AN4 I
19 P85/AN5 I
20 P86/AN6 I
21 P87/AN7 ADI VER Version input
22 P71/INT1 I
23 P72/INT2 I /POWERDOWN Power down detect
24 P73/INT3 I REM REM input
25 S0/T0 O 13G FL segment
26 S1/T1 O 12G FL segment
27 S2/T2 O 11G FL segment
28 S3/T3 O 10G FL segment
29 S4/T4 O 9G FL segment
30 S5/T5 O 8G FL segment
31 S6/T6 O 7G FL segment
32 S7/T7 O 6G FL segment
33 S8/T8 O 5G FL segment
34 S9/T9 O 4G FL segment
35 S10/T10 O 3G FL segment
36 S11/T11 O 2G FL segment
37 S12/T12 O 1G FL segment
38 S13/T13
39 S14/T14
40 S15/T15
No. Port I/O Name Function
41 VDD2 I VDD +5V
42 VP I VDDVPP —24V
43 S16/PC0 O P1 FL segment
44 S17/PC1 O P2 FL segment
45 S18/PC2 O P3 FL segment
46 S19/PC3 O P4 FL segment
47 S20/PC4 O P5 FL segment
48 S21/PC5 O P6 FL segment
49 S22/PC6 O P7 FL segment
50 S23/PC7 O P8 FL segment
51 S24/PD0 O P9 FL segment
52 S25/PD1 O P10 FL segment
53 S26/PD2 O P11 FL segment
54 S27/PD3 O P12 FL segment
55 S28/PD4 O P13 FL segment
56 S29/PD5 O P14 FL segment
57 S30/PD6 O P15 FL segment
58 S31/PD7 O
59 S32/PE0 I/O
60 S33/PE1 I/O
61 S34/PE2 I/O
62 S35/PE3 I/O
63 S36/PE4 I/O
64 S37/PE5 I/O
65 P00 O
66 P01 O
67 P02 O
68 P03 O
69 P04 O /TMUTE Tuner mute
70 P05 O
71 P06 O RSYN Block Synchronous Detect Output
72 P07 O RCE Chip Enable
73 VSS2 I GND GND
74 P10/S00 O RDI Data Input
75 P11/SI0 SIN RDO Data Output
76 P12/SCK0 SCL RCL Clock Input
77 P13/SO1 I PLLDAT-i n Data input from PLL
78 P14/SI1 O PLLDAT-ou t Data output for PLL
79 P15/SCK1 O PLL-CLK PLL clock
80 P16/BUZ O PLLCE PLLCE
KEY INPUT
Key Input 1 2 3 4 5 6 7
Resistance (Ω) 0k 1.8k 2.7k 3.9k 6.8k 13k 39k
Extent of AD 00H~15H 16H~3DH 3EH~64H 65H~8AH 8BH~B0H B1H~D3H D4H~F0H
Extent of Voltage (V) 0.00~0.41 0.41~1.19 1.19~1.95 1.95~2.70 2.70~3.44 3.44~4.12 4.12~4.69
Pin No.14 KEYIN1 P3 P4 P5 P6 P7 P8
Pin No.15 KEYIN2 MODE EDIT (KMODE) MEMORY PAGE P1 P2
Pin No.16 KEYIN3 FREQ/TEXT PTY SEEK MODE PTY SEEK START EON FM/AM (MW/LW) TUNING DOWN TUNING UP

TX-497
17
DISPLAY DATA (13-BT-152GK)
PIN NO. 1 2 3 456789101112131415161718
CONNECTION F1 NP NP P15 P14 P13 P12 P11 P10 P9 P8 P7 P6 P5 P4 P3 P2 P1
PIN NO. 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35
CONNECTION NC 1G 2G 3G 4G 5G 6G 7G 8G 9G 10G 11G 12G 13G NP NP F2
PIN CONNECTION
NOTE:
1) F1, F2 ................. Filament
2) NP....................... No pin
3) NC....................... No connection
4) DL ....................... Datum line
5) 1G~13G .............. Grid
13G 12G 11G 10G 9G 8G 7G 6G 5G 4G 3G 2G 1G
P1 PRESET aaaaaaaaaaa AUTO
P2 MEMO bbbbbbbbbbb kHz
P3 □ (PS) ccccccccccc MHz
P4 PS ddddddddddd ST
P5 □ (PTY) eeeeeeeeeee B1
P6 PTY fffffffffff B2
P7 □ (RT) ggggggggggg B3
P8 RT hhhhhhhhhhh B4
P9 □ (CT) jjjjjjjjjjj B5
P10 CT kkkkkkkkkkk B6
P11 EON mmmmmmmmmmm S1
P12 NEWS nnnnnnnnnnn EDIT
P13 INFO pppppppppppPTYHOLD
P14 AFFAIRS rrrrrrrrrrr −
P15 SPORT ttttttttttt −
ANODE CONNECTION

ABCDEFGH
1
2
3
4
5
6
TX-497
18
■BLOCK DIAGRAM
5
7MF
Ω
DNG
MA
FM FRONT END
P
M
AFR REXI
M2L 3L4
L6621AL:2
CI
01
Q4,3Q31
Q
7L
PMA
FIMF
TEDLEVEL
9L CI
M
AREC RETLIF
P
MA
F
R
AM COIL PACK PK2
TNA LIOC
CSO LIOC
205Q TESER
SOMC
GNINUT LORTNOC
ISL
105CI
A024668CL
U
PC
t
i
b
8
B*
205D
105V
205
CPUKCAB
105Q REWOP NO
SUBATAD&LORTNOC
REMOTE
CONTROL
RECEPTER REWOP YLPPUS
105U
SW521
POWER SW
SW521
POWER SW
J, U, C, T, A, B, G, E models
B, G, E models
R, L models
PV
B
*
V21
V5
DRAOBYEK
03127CL:
1CI
915~105WS
REXIM
CSO
CGA
61Q01L
FM/AM
MUTING
LLP
ETUM.DNITS
3LX
21L
31L
F
PL
hcL
hcR
E
TUM WS
02,91Q 32,22Q
LORTNOC
REDOCED
SISAHPME-ED
MA TED
RETEM.S DEL REVIRD
5L
51
Q
ERUTARDAUQ
TED
TEDMF LIOC
FI
REFFUB
FI
REFF
UB
2,1RV
5,2Q
CSO
R
E
F
FUB
1KP
~
~
~,
~
LLP MOC-
CIFIMF/MA
1043AL:3CI
CIXPM
4
2
1
51
4
1
3
4
5
6
21
22
12
71
8
1
0
2
91
61
32
2/1
ECNE
R
EFER RE
D
IVID
RET
N
UOCW
O
LL
A
W
Sstib471/1,61/1
EL
BAMM
ARG
O
RP
st
ib
2
1REDIVID
DATA SHIFT REGISTER LATCH
REWOP N
OTESER
C
2
B
F/I L
A
SREVINU RETNUOC
ROTCETEDESAHP PMUPEGRAHC
KCO
LN
UROTCETED
987
01
11 31
2
&1 &2
~
&4 &6
~
IC401
LC72720
RDS

ABCDEFGH
1
2
3
4
5
6
TX-497
19
■PRINTED CIRCUIT BOARD (Foil side) Lead Free Solder Used
POWER
DG VP FL2 FL1
12 13
124
112
1324
111
1222
AM ANT
GNDFM ANT LINE OUT
LR
TP3
1P
T
TP2
AM SENSITIVITY
SIGNAL
METER
DISCRIMINATOR
BALANCE MONAURAL
DISTORTION
U, C, R, J B, G
STEREO
DISTORTION
SEPARATION
B* DNGNA
B-
GNDD
5V
*B /TMUT RSYN
RCE
RDI
RDO
RCL
PLDO
PLDI
PLCL
PLCE
/MMUT
MTR
VER
GNDD
TUNER P.C.B.
(Side A)
(Side A)
OPE P.C.B. (3)
OPE P.C.B. (1)
OPE P.C.B. (2)
B*
ANGND
B
-
(Side A)
(Side A)
OPE P.C.B. (4) (Side A)
R, L Models
DG
VP
FL2
FL1
GNDD
5V *B /TMUT
RSYN
RCE
RDI
RDO
RCL
PLDO
PLDI
PLCL
PLCE
/MMUT
MTR
VER
GNDD
8765432 1
FREQ/TEXTEON
MODESTART
AUTO/MAN’L
TUNING
MAN’L/AUTO FM
TUNING MODE MEMORY
FM/MW/LW
FM/AM
EDIT
PTY SEEK
A/B/C/D/E

ABCDEFGH
1
2
3
4
5
6
TX-497
20
■PRINTED CIRCUIT BOARD (Foil side) Lead Free Solder Used
(Side B)
OPE P.C.B. (3)
OPE P.C.B. (1)
(Side B)