– 2 – – 4 –– 3 –
WM-FX453/FX455
SERVICE MANUAL
SUPPLEMENT - 4
File this Supplement with the Service Manual.
Subject :
r
CHANGE OF BOARDS (WM-FX453 : US Model only)
DISPLAY BOARD : 1-663-492-14 / 1-670-650-12
MAIN BOARD : 1-663-491-14 / 1-670-649-12
US Model
AEP Model
E Model
WM-FX453/FX455
Canadian Model
Chinese Model
WM-FX453
Due to this change, only electrical adjustment, explanation of IC terminals, printed wiring boards, schematic diagram and a electrical parts
list of WM-FX453 (US model) are described in this supplement-4.
For other information, please refer to the previously issued WM-FX453/FX455 service manual (9-923-169-11), supplement-1
(9-923-169-81), Supplement-2 (9-923-169-82) and Supplement-3 (9-923-169-83).
(ECN-WM801299/WM801300)
1-670-649
-12
1-670-650
-12
[DISPLAY BOARD] (SIDE A)
[MAIN BOARD] (SIDE B)
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CHANGE OF BOARDS (WM-FX453 : US model only)
NEW TYPE IDENTIFICATION
Frequency Coverage Adjustment
Setting :
[MAIN BOARD] (SIDE B)
AM IF ADJUSTMENT
Adjust for a maximum reading on level meter.
T1 450kHz
AM FREQUENCY COVERAGE ADJUSTMENT
Adjust part Frequency display reading on digital
voltmeter.
L3 530kHz 1.45 – 1.55V
AM TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter.
L4 620kHz
CT2 1,400kHz
FM FREQUENCY COVERAGE ADJUSTMENT
Adjust part Frequency display reading on digital
voltmeter.
L2 108MHz 9.95 – 10.05V
Confirmation 87.5MHz more than 2V
FM TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter.
L1 87.5MHz
Confirmation 108MHz
TUNER SECTION 0dB = 1µV
AM Section
BAND : AM
FM Section
BAND : FM
[MAIN BOARD]
(SIDE B)
• Repeat the procedures in each adjustment several times, and the
frequency coverage and tracking adjustments should be finally
done by the trimmer capacitors.
AM RF signal
generator
30% amplitude modulation by 400Hz
signal.
Output level : as low as possible
Put the lead-wire
antenna close to
the set.
set
16
Ω
J301 (phones)
level mete
digital voltmete
(DC range)
(VT)
(GND)
GND
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ELECTRICAL ADJUSTMENT
(WM-FX453 : US model only)
(Service Manual See page 8, 9)
FM RF signal
generator
22.5kHz frequency deviation by
400Hz signal.
Output level : as low as possibl
0.01
µ
F
(GND)
Adjustments Location :
[MAIN BOARD] (SIDE A)
L3 : AM Frequency Coverage Adjustment
L1 : FM Tracking Adjustment
L4 : AM Tracking Adjustment
CT2 : AM Tracking Adjustment
T1 : AM IF Adjustment
L2 : FM Frequency Coverage Adjustment
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EXPLANATION OF IC TERMINALS (Service manual See page 10)
IC701 µPD170172GB-555-1A7 (ND DRIVE, SYSTEM CONTROL) (WM-FX453 : US model only)
Pin No. Pin name I/O Description
1 INIT – Not used (Open).
2 BAND AM O BAND AM ON selection output.
–––––––
3 BAND AM – Not used (Open).
4 MEGA BASS I MEGA BASS ON/OFF input.
––––––––––––
5 IF ON O IF ON/OFF control.
6 – Not used (Open).
7 RADIO ON O Radio power ON/OFF control.
8 – Not used (Open).
9 – Not used (Open).
10 KEY IN 1 I Key input.
11 KEY IN 2 I Key input.
12 KEY IN 3 I Key input.
13 KEY IN 4 I Key input.
14 MUTE O Mute signal output.
15 DOLBY O Dolby ON/OFF control.
16 – Not used (Open).
17 IF IN I IF signal input.
18 GND – Ground.
19 EO O PLL error output.
20 VCO (AM) I VCO input.
21 VCO (FM/TV) I VCO input.
22 VDD2 – Power supply terminal (+3V).
23 VDD1 – Power supply terminal (+3V).
24 X0 – System clock oscillator (75kHz).
25 X1 – System clock oscillator (75kHz).
26 VDD5 – Power supply (+3V).
27 VDD3 – Power supply (+3V).
28 CAP 1 – Pins connecting capacitors for doubler circuits gemerating the ND drive voltage.
29 CAP 2 – Pins connecting capacitors for doubler circuits gemerating the ND drive voltage.
30 VDD4 – Power supply (+3V).
31 – 34 COM 0 – 3 O ND common output.
35 – 49 LCD 0 – 14 O ND segment drive output.
50 CE I The internal reset circuit functions when low becomes high.
51 TAPE ON I TAPE ON signal input.
52 BEEP O BEEP signal output.
53 KEY OUT 1 O Key scan output.
54 KEY OUT 2 O Key scan output.
–––––––
55 BAND AM – Not used (Open).
56 KEY OUT 4 O Key scan output.
Ver 1.0 1999. 01
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TEL 13942296513 QQ 376315150 892498299
TEL 13942296513 QQ 376315150 892498299
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