Sanyo C20VTI I-M User manual

SERVICE MANUAL Colour Television with
=1’1’yo
FILE NO
Model NO. C20VTI I-M@
Videocassette Recorder (New Zealand /Oceania)
Service Ref. No. C20VT11 -M@-00
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Contents
Safety Precautions, X-Radiation Precautions ................. ~
Specifications .....................................................................
1. Mechanical Disassembles
1-1. Cabinet back removal ............................................ 4
1-2. Chassis removal .................................................... 4
1-3. Video mechanism removal .................................... 5
1-4. Service procedure ................................................. 7
1-5. Replacement of the reel drive belt ........................ 8
1-6. Video mechanism disassemblies .......................... 8
1-7. Cassette mechanism assembly .............................11
2, Service Mode ................................................................l2
3. Power Circuit Protection and
Self Diagnosis Display
3-1. Power circuit protection ........................................ 13
3-2. Power circuit problem self diagnosis .................... 13
3-3. VCR self diagnosis ................................................l4
4. ICS Pin Description
4-1. IC800 (CPU) pin description .................................15
4-2. IC1930 (DAC) pin description., .............................l5
5. Service Adjustments (TV Section)
+15V/+1 15V, Vertical size/center, Focus adjustment..l 6
Grey scale, AGC, Horizontal center adjustment .........l7
Horizontal width adjustment, High voltage check ........18
Clock frequency confirmation .......................................l8
6. WF Adjustment ............................................................. 19
7. A7TAdjustment ............................................................2O
8. Purity and Convergence Adjustment ...........................21
Product Code: 111321218
Original Version
Chassis Series: TC2-A
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9. VCR Main Mechanism Parts Location
9-1. Mechanism ass’y (Top view) .................................... 22
9-2. Mechanism ass’y (Bottom view) ............................... 23
9-3. Front loading mechanism .......................................... 23
10. Mechanism Dismantling and Reassembling
10-1. Cassette drive gear (Right) ................................... 24
10-2. Cassette drive gear (Left) ..................................... 25
10-3. COMPL motor bracket (Loading motor block) ..... 26
10-4. Tape loading mechanism ...................................... 29
10-5. Capstan motor ....................................................... 32
11. VCR Service Adjustments
11-1. Test points for tape path adjustment .................... 33
11-2. Location of adjustment point ................................. 33
11-3. Sewicejigs ............................................................ 34
11-4. Mode selector (VHJ-0050) handling instruction ... 35
11-5. Tape path adjustment ........................................... 37
11-6. Servo circuit adjustment ...................................... 39
11-7. Audio circuit adjustment ...................................... 39
11-8. Video still V-lock adjustment ................................ 40
12. Mechanism Maintenance and Checking
12-1. Periodic checking and maintenance items .......... 41
12-2. l_#mwo~e~roceedwhen the cassette cannot be
................................................................ 42
13. Cabinet Parts tist ........................................................... 43
14. Video Section Parts List ................................................ 44
15. TV Section Chassis Electrical Parts List ........................ 49
REFERENCE NO. SM 520130
(E7WY)

Safety Precautions
An isolation transformer should be connected in the power
line between the receiver and the AC line before any
service is performed on the receiver.
X- Radiation Precautions
The primary source of X-RADIATION in television
receiver is the picture tube. The picture tube is specially
constructed to limit X-RADIATION emission. For
continued X-RADIATION protection, the replacement
tube must be the same type as the original including
suffix letter. Excessive high voltage may produce
potentially hazardous X-RADIATION. To avoid such
hazards, the high voltage must be maintain within
specified limit. Refer to this service manual for specific
high voltage limits. If high voltage exceeds specified limits,
take necessary corrective action. Carefully follow the
instructions for +B1 volt power supply adjustment, and
high voltage check to maintain the high voltage within the
specified limits.
–2–

Specifications
TV section
Power source AC 110-240 Volts, 50/60 Hz.
Receiving system PAL(B/G, D/K, 1,M/M), SECAM(B/G, D/K,1,M/M), NTSC(B/G, D/K, 1,M/M)
Channel coverage VHF: E2– E12, J1 –J12, A2-A13, C1 –C12, R1 –R12
CATV: S1 –S20, X, Y, Z
UHF:E21 –E69, J13 –J62, A14 –A69, C13 –C57
Aerial input impedance 75 Q
Audio output (Music )2.0 w
Ext. terminals AV inputs:
Video input (Phono jack) X1(1.OVp- p, impedance 75 S2)
Audio input (Phono jack) X1(142mVrms, impedance more than 47k S2)
AV output:
Video output (Phono jack) X1(1.OVP- p, impedance 75 S2)
Audio output (Phono jack) x1(142mVrms, impedance less than 1kQ)
Set dimensions
Set weight
VCR section
Format
Video signal
Video heads
Tape speed
Headphone jack: Mini. jack X1
494(W) x500(H) x473(D)mm
approx. 23.0 Kg
VHS
PAL/MESECAM/NTSC
2heads
PAUMESECAM:
SP: 23.39 mm/see.
LP: 11.70 mm/see.
NTSC:
SP: 33.35 mm/see.
LP: 16.67 mm/sec.(PIayback only)
EP: 11.12 mm/see.
Timer indication 24-hour indication
Power failure backup Approx. one hour
Specifications subject to change without notice.
–3–

1. Mechanism Disassembles
1-1. Cabinet Back Removal
1)Remove 9screws.
2) Pull the cabinet back off and remove the cabinet back.
1
II 1IIII
IEL
--
1-2. Chassis Removal
1)Remove the cabinet back.
2) Remove 2screws fixing the video mechanism.
3) Disconnect “KOS’’(Speaker lead) and “K6B’’(Degaussing Coil lead) on the Power/Deflection Unit.
4) Remove the chassis (Main Unit and Power/Deflection Unit) completely by sliding straight back.
Screw
K(
K6B”
Power/Def in Unit
-/
Video Mechanism
/
/Screw
–4–

L1-3. Video Mechanism Removal
1) Remove the chassis (Main Unit and Power/Deflection Unit) completely.
2) Remove the VIDEO UNIT by removing 2screws.
3) Disconnect “K2A, “K213”, “K2D on the Main unit.
4) Take off lead wires and AC cord from clamps on the shield cover.
5) Separate the Main unit from the Power/ Deflection Unit.
.6) Disconnect “KY” lead from the Main Unit.
Power/Deflection
Unit
L
7) Remove the shield
11 \-’l
I:rewwi
I
I#l
II
AC Cord “Main Unit
Video Mechanism
cover by removing 3screws.
Video Unit
/
,KY
Shield Cover
(Video Mechanism)
Screw
–5–

8) Remove the shield cover by removing 2screws (screw-A).
9) Remove the screw-B.
IF
Sc
Shield
:rew-A
Cover
Main U
10) Remove 3screws on the back of the Main unit.
11) Remove the Video Mechanism from the Main unit.
BACK SIDE
—Screw-B
—---=4
Clamp
Screw
—
Pre-amp. Unit
Slide the Video Mechanism
to take off the clamps.
Video Mechanism
Main Unit
–6–

1-4. Service Procedure
1)Turn the Video mechanism 180 degrees, and set as illustrated bellow.
2) Reconnect “k2A, “K2B” and “K2D.
J
/
w
i:
N
Z~Ou_~ jla,
Power/Deflection Unit
Video Mechanism II P
\Turn 180 degrees
=Power/Deflection Unit
Main Unit
–7–

1-5. Replacement of the reel drive beltBELT
1) Remove the Video Mechanism from the Main Unit.
2) Replace the reel drive belt,
\JReel Drive Belt
..
1-6. Video mechanism disassembles
1)Disconnect the flat cables from “CN9301” and “CN81 1”.
2) Remove the Pre-amp. unit by removing the screw.
3) Separate the Video Mechanism from the Main unit.
/
Main Unit \\\\ f
\\&n3-a ~deounit
~
CN811
–8–

4) Remove the screw-A (2 screws), screw-B and the screw-C.
.
5) Remove the screw-D (2 screws).
(Unlock by pressing the clamp-A~ Slide the cassette base in the direction of the arrow
4Remove the screw-D)
6) Remove the Video Mechanism from the mechanism holder.
Screw-A
Screw-B
Screw-A
Screw-C
99
\
\4
\~deoMec~ismHo,der
Cassette Base
>
Screw-D
I
/
/
/
–9–

7) Remove the Cassette Door as follows.
Washer Spring
\
~-
d
Cassette Door
*\Cassette Door
8) Remove the cassette mechanism as follows.
@Remove two screws.
@Disconnect three connectors.
@Cut the wire band.
@Remove the cassette mechanism by sliding and unlocking the two hooks.
Video Mechanism
Wire Band
Connector
FTE Head
Screw
_—.
-Y&!!!%7
Hook
Cassette
Mechanism
~Cassette Door
Screw-
–lo–