Sony TC-WE635 User manual

– 1 –
SERVICE MANUAL
US Model
Canadian Model
AEP Model
UK Model
E Model
Australian Model
Chinese Model
STEREO CASSETTE DECK
MICROFILM
SPECIFICATIONS
Dolby noise reduction extension manufactured under license
from Dolby Laboratories Licensing Corporation.
HX Pro originated by Bang & Olufsen.“DOLBY”, the double-D
symbol aand “HX PRO” are trademarks of Dolby Laboratories
Licensing Corporation.
TC-WE635
— Continued on next page —
Model Name Using Similar Mechanism TC-WE425/WE525/WR681
Transport Mechanism Type TCM-230ASR4/HSR4

– 2 –
SAFETY-RELATED COMPONENT WARNING!!
COMPONENTS IDENTIFIED BY MARK !OR DOTTED LINE
WITH MARK !ON THE SCHEMATIC DIAGRAMS AND IN
THE PARTS LIST ARE CRITICAL TO SAFE OPERATION.
REPLACE THESE COMPONENTS WITH SONY PARTS WHOSE
PART NUMBERS APPEAR AS SHOWN IN THIS MANUAL OR
IN SUPPLEMENTS PUBLISHED BY SONY.
ATTENTION AU COMPOSANT AYANT RAPPORT
À LA SÉCURITÉ!!
LES COMPOSANTS IDENTIFIÉS PAR UNE MARQUE !SUR LES
DIAGRAMMES SCHÉMATIQUES ETLALISTE DESPIÈCES SONT
CRITIQUES POUR LA SÉCURITÉ DE FONCTIONNEMENT. NE
REMPLACER CES COMPOSANTS QUE PAR DES PIÈCES SONY
DONT LES NUMÉROS SONT DONNÉS DANS CE MANUEL OU
DANS LES SUPPLÉMENTS PUBLIÉS PAR SONY.
SAFETY CHECK-OUT
After correcting the original service problem, perform the follow-
ing safety checks before releasing the set to the customer:
Check the antennaterminals, metal trim, “metallized”knobs, screws,
and all other exposed metal parts forAC leakage. Check leakage as
described below.
LEAKAGE
The AC leakage from any exposed metal part to earth Ground and
from all exposed metal parts to any exposed metal part having a
returnto chassis,must not exceed0.5 mA (500microampers). Leak-
age current can be measured by any one of three methods.
1. A commercial leakage tester, such as the Simpson 229 or RCA
WT-540A. Follow the manufacturers’ instructions to use these
instruments.
2. A battery-operated AC milliammeter. The Data Precision 245
digital multimeter is suitable for this job.
3. Measuring the voltage drop across a resistor by means of aVOM
or battery-operatedAC voltmeter.The “limit” indication is 0.75
V, so analog meters must have an accurate low-voltage scale.
The Simpson 250 and Sanwa SH-63Trd are examples of a pas-
sive VOM that is suitable. Nearly all battery operated digital
multimeters that have a 2V AC range are suitable. (See Fig. A)
Fig. A. Using an AC voltmeter to check AC leakage.
0.15 µ F
To Exposed Metal
Parts on Set
1.5k
Ω
AC
voltmeter
(0.75V)
Earth Ground

– 3 –
MODEL IDENTIFICATION
–Back panel–
PARTS No. MODEL
3-032-412-0πUS model
3-032-412-1πCND model
3-032-412-2πAEP model
3-032-412-3πUK model
3-032-412-4πAUS model
3-032-412-5πSP, MY model
3-032-412-6πCH model
• Abbreviation
CND : Canadian model
SP : Singapore model
MY : Malaysia model
AUS : Australian model
CH : Chinese model
TABLE OF CONTENTS
1. GENERAL .......................................................................... 4
2. DISASSEMBLY
2-1. Case ...................................................................................... 5
2-2. Front Panel Assembly ........................................................... 5
2-3. Cassette Lid Assembly (Deck A/B) ...................................... 6
2-4. Mechanism Deck Assembly (Deck A/B) .............................. 6
2-5. Leaf SW (REC/PB) Board (DeckA/B) ................................ 7
2-6. Pinch Lever (FWD)/(REV) Assembly (DeckA/B)............... 8
2-7. Flywheel (FWD)/(REV) Assembly (Deck A/B) ................... 8
2-8. Mechanical Block Assembly (Deck A/B) ............................. 9
2-9. Head Relay (REC/PB) Board (DeckA/B) ............................ 9
3. SERVICE MODE ............................................................ 10
4. MECHANICAL ADJUSTMENTS............................... 11
5. ELECTRICAL ADJUSTMENTS ............................... 11
6. DIAGRAMS
6-1. Circuit Boards Location ......................................................15
6-2. Printed Wiring Board – Main Section –.............................. 17
6-3. Schematic Diagram – Main Section – (1/4)........................ 19
6-4. Schematic Diagram – Main Section – (2/4)........................ 21
6-5. Schematic Diagram – Main Section – (3/4)........................ 23
6-6. Schematic Diagram – Main Section – (4/4)........................ 25
6-7. Printed Wiring Board – Deck Section –.............................. 27
6-8. Schematic Diagram – Deck Section – ................................ 28
6-9. Schematic Diagram – Display Section – ............................ 29
6-10. Printed Wiring Board – Display Section – ....................... 31
6-11. Schematic Diagram – Panel Section – .............................. 33
6-12. Printed Wiring Board – Panel Section –........................... 35
6-13. Schematic Diagram – Power Section – ............................. 37
6-14. Printed Wiring Board – Power Section – ......................... 39
6-15. IC Pin Function ................................................................ 41
7. EXPLODEDVIEWS
7-1. Case Section ........................................................................ 43
7-2. Chassis Section ................................................................... 44
7-3. Cassette Holder Section ...................................................... 45
7-4. Front Panel Section ............................................................. 46
7-5. Tape Mechanism Section (TCM-230ASR4/HSR4) ............47
8. ELECTRICAL PARTS LIST ........................................ 48
Part No.

– 4 –
SECTION 1
GENERAL
LOCATION OF PARTS AND CONTROLS
1Ubutton
2RESET (Deck A) button
3MEMORY (Deck A) button
4RESET (Deck B) button
5MEMORY (Deck B) button
6AUTO REC LEVEL indicator
7REC LEVEL knob
8FADER button
9ARL button
10 SYNCHRO button
11 PHONES jack
12 HIGH/NOMAL button
13 A+B REC button
14 DECK B button
15 DECK A button
16 (AMS) )(Deck B) button
17 0(AMS) (Deck B) button
18 ·(Deck B) button
19 ª(Deck B) button
20 REC r(Deck B) button
21 §(Eject) (Deck B) button
Front Panel
22 REC MUTING R(Deck B) button
23 PAUSE P(Deck B) button
24 p(Deck B) button
25 DOLBY NR B/C switch
26 DOLBY NR OFF/ON FILTER
27 ·/FRONT (Deck A) button
28 ª/BACK (Deck A) button
29 REC r(Deck B) button
30 REC MUTING R(Deck A) button
31 §(Eject) (Deck A) button
32 PAUSE P(Deck A) button
33 p/CLEAR (Deck A) button
34 (AMS) )(Deck A) button
35 0(AMS) (Deck A) button
36 DISPLAY button
37 CHECK button
38 SET button
39 RMS/START button
40 PITCH CONTROL knob
41 PITCH CONTROL button
42 DIRECTION switch
• AMS is the abbreviation forAutomatic Music Sensor.
10
8
9
24 67
135
2321
22
20
11
131415 12161819 17
24
25
26
27
28
2930
31
33 32
34
35
36
3738
39
40
41
42

– 5 –
SECTION 2
DISASSEMBLY
Note : Follow the disassembly procedure in the numerical order given.
2-1. CASE
2-2. FRONT PANEL ASSEMBLY
1 Screw
(BVTP 3x8)
2 Two Screws
(Case 3 TP2)
3 Two Screws
(Case 3 TP2)
4 Case
!™ Screw
(BVTP 3x8)
!¢ Screw
(BVTP 3x8)
!£ Screw
(BVTP 3x8)
!¶ Two screws
(BVTT 3x6)
!§ Claw
!∞ Claw
!• Front panel assy
9 CN1002
0 CN1003
2 CN807
1 CN5802
3 CN803
4 CNA806
5 Flat type wire
(Deck A)
!¡ CN002
6 Flat type wire
(Deck B)
7 Screw
(BVTP 3x8)
8 Wire

– 6 –
2-3. CASSETTE LID ASSEMBLY (DECK A/B)
2-4. MECHANISM DECK ASSEMBLY (DECK A/B)
2 Four claws
1 Push the EJECT button.
3 Cassette lid assy
1 Two screws
(BVTP 2.6x8)
3 Mechanism deck assy
2 Two screws
(BVTP 2.6x8)

– 7 –
2-5. LEAF SW (REC/PB) BOARD (DECK A/B)
1 Two screws
(PS 2.6x6)
2 Capstan motor assy
8 Belt (capstan)
3 Wires
5 Screw
(BVTT 2x4)
4 Screw
(BVTT 2x4)
6 Claws
Claws
7 LEAF SW (REC/PB) board
When installing,
pull the belt (capstan)
put around claws.
a
a
b
b

– 8 –
2-6.PINCH LEVER (FWD)/(REV) ASSEMBLY (DECK A/B)
2-7. FLYWHEEL (FWD)/(REV) ASSEMBLY (DECK A/B)
4 Pinch lever (FWD) ass
y
2 Pinch lever (REV) assy
1 Claw
3 Claw
1 Belt (FR2)
3 Flywheel (FWD) assy
6 Flywheel (REV) assy
4 Washer
7 Washer
2 Stopper washer
5 Stopper washer

– 9 –
2-8. MECHANICAL BLOCK ASSEMBLY (DECK A/B)
2-9. HEAD RELAY (REC/PB) BOARD (DECK A/B)
2 Two screws
(BVTT 2x3.5)
1 Torsion spring
5 Reverse slider
4 Mechanical block assy
3 Two screws
(BVTT 2x3.5)
3 Tension spring (HEAD)
2 HEAD RELAY (REC/PB) board
1 Screw
(
BVTT 2x4
)
4 Head deck assy

– 10 –
RESET 0
MEMORY 1
RMS/START 2
SET 3
CHECK 4
DISPLAY 5
0(AMS) 6
(AMS) )7
p/CLEAR Grid check display (*1)
9/BACK 8
(/FRONT 9
PAUSE PA
REC MUTING Rb
REC rC
DIRECTION MODE switch
Aª
dPLAY
RELAY ·
A deck side
Button Display
KEY CHECK & DISPLAY CHECK MODE
While pressing the ª/BACK (A deck) and REC MUTING R(B deck) buttons with the power off, press the Ubutton to turn on the
power.
The fluorescent display tube displays the number or special message corresponding to the button pressed.
The message displayed differs according to the position of the switch.
SECTION 3
SERVICE MODE
RESET 0
MEMORY 1
DECK A 2
DECK B 3
A+B REC 4
HIGH/NOMAL 5
0(AMS) 6
(AMS) )7
pSegment check display (*2)
ª8
·9
PAUSE PA
REC MUTING Rb
REC rC
FADER d
ARL E
SYNCHRO All lit
DOLBY NR switch (*3)
OFF ª
B PLAY
C·
B deck side
Button Display
Grit check display (*1)
Segment check display (*2)
RMS
(*3) The DOLBY NR switch consists of a pair of switches.
B and C are valid only in the ON or ON FILTER state.