Sanyo CZP2940TXN User manual

SAjI/YO
SERVICE MANUAL
.
L
QSpecifications
Colour Television
IFILE NO. I
Model No. CZP2940TXN
(New Zealand)
Service Ref. No. CZP2940TXN -00
t
1
Power Source .................... AC220-240V, 50Hz
Television System ............. B/G
PAL (AV input: PAlJNTSC/NTSC4.43)
Channel Coverage ............. VHF 1 – 11
UHF: 21 – 69
Video IF ............................. 38.9 MHz
Sound IF.., ......................... 33.4 MHz
Aerial Input Impedance..,.., 75 !2
Ext. Terminals .................... Video inputs: Phono jack x 3 lVP –p, 75 Q)
[
S-terminal x 2 DIN 4pm separate,
Y/C signal input)
Audio inputs: Phono jack (R/L x 3 (436mVrms,
A
more than 40K )
Audio monitor outputs: Phono jack (R/L) x 1 (436
Vrms, less than 600 S2)
TV outputs (video and audio :
bVideo output- hono jack x 1
Audio output- Phono jack (R/L) x 1
External speaker terminals: 8S2, output max. 5W
Headphone jack: Mini. stereo jack
Dimensions ........................ 797(W) x596(H) x487(D)mm
Weight ............................... approx. 50Kg
wSpecifications subject to change without notice.
Product Code: 111315716
Original Version
Chassis Series: A8- A29
Give complete “SERVICE REF. No.” for parts
order or servicing. It is shown on the rating plate
at the cabinet back of the unit.
This T.V. receiver will not work properly in
foreign countries where the television trans -
mission system and power source differ from the
design specifications. Refer to the specification
table. I
REFERENCE NO. SM 520014
E6-IV

I
A
I
%
TU,Band
~A “PC’8”CX1
Control
AN5836
i}! I1~–.
AV Switch
Video TA8747N
3ACK TML
&
$’ Y/c
3CB Ass~ s
Digital
COMB Comb
FILTER Filter PCB ASSY (pAL/
NTSC)
TEXT PCB ASSY
m.
I
Colour Decoder/ I
HN Driver
TDA9 160
➤
4SCL xWA
YFeature Controller
CXA1 420P TDA4685
R-YB-Y
f,9 2&SCL
2zSLlA
+~i&6\
RGB
.i
UAIN PCB ASSY
Speaker
al CRT PCB ASSY
I_!mzzl —A
,,@@, --pJ
r. . . . . . 1
I t 1
,HV
FBT
H.D~ve ‘-OuT
‘m- “
~~~ *
>=!!
Vettical Output Deflection
TDA8172 Yoke
H
POWER &DEF.
PCB ASSY
ki- ~,
CPU I*C BUS
Time Base M37102M8 Memory
LA7212 24 C04AIP
TimeBase 6SCL
Video(TV) 5SDA
!1 9V 64 5V 2
Digital Control
(Audio)
uPD6326C I*C BUS
11:Volume Data, Switch
Band 12:Swround clock
4Load 4066B
LA791O 13:Balance
14:Treble -i4 I...- 1
,8
15:aass
Band 21 :SCL 4SCL 3:SCL ;SCL g
Tu 22SDA <SCUSDA’ 2SDA 1:sDA ISDA :
.-- .-d 1
Band Data
MPU PCB ASSY

Circuit Description
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1-1. Video signal routing
Video signals output from IF pack are input to AV
switching IC (TA8747N). In this IC, they are switched to
AV signals. Colour. Yor composite signals output from
TA8747N are input to Colour Decoder &H/V Drive IC
(TDA91 60) and Ysignal is input to the Teletext Decoder.
All functions of TDA9160 are controlled by I’C Bus lines
(SCL:Serial Clock/ SDA:Serial Data) of CPU. Ysignal
output from TDA9160 is input to YFeature IC (CXA
1420P) for the aperture control and black expand and
input to the velocity circuit. Ysignal output from CXA
1420P is input to Video Controller IC (TDA4685). Colour
differential signals (R- Y/B- Y) demodulated byTDA9160
are input to 1Hdelay IC (TDA4661 )as 1Hdelay and
matrix and output to TDA4685 as proper colour
differential signals. In TDA4685, colour differential signals
are converted to RGB signals, RGB signals from Teletext
decoder or CPU are super- imposed on them, and RGB
signals are output to RGB Drive IC (TDA6101 Q/N2). C)(A
1420P and TDA4685 also are controlled by I*C Bus lines.
1-2. Audio signal routing
SIF signals output from IF pack are input to A2 stereo
decoder and NICAM stereo decoder. Stereo signals
detected by both decoders are input to AV switching
IC(TDA8747N). After switching to external audio signals
in this IC, they are input to Sound Selector IC
(MC140538CP) as selecting an L channel, an Rchannel
or both channels. Audio signals output from MC
140538CP are input to the Surround IC as mixing
surround signals in surround mode. Output signals are
input to Audio Control IC (AN5836). Bass, treble,
balance and volume control is applied to signals, which
are amplified by Audio Output IC (LA4720), and output to
the speakers.
2. CPU (IC801) Pin Description
Pin 1: Oscillator for OSD (in)
Pin 2: Oscillator for OSD (out)
Pin 3: ABL voltage (in)
Ov- 5V
Pin 4: Brightness sensor (in)
Ov- 5V
Pin 5: Remote control input (active low)
Pin 6: Tuning voltage (out)
Pin 7: Band data (out)
Pin 8: Band data (out)
Pin 9: AFT input (1)
L:No signal
PinlO: AFT input (2)
L: No signal
Pinl 1: Am ON/OFF (out)
L: AFT ON
Pinl 2: Picture (TEXT) ON (in)
L: TEXT/lV mixed mode
–2–
Pinl 3: 12CBUS switching (out)
H: Normal
Pin14: RGB IGNOR output
H: IGNOR ON
Pinl 5: Woofer ON/OFF output
H:Woofer ON
Pinl 6: Not used
Pinl 7: Forced time base input
L: Forced time base is input (Factory mode)
Pinl 8: Setting to factory mode (in)
L: Factory mode
Pinl 9: Overload protector input
L: ProtectorON
Pin20: SCART option switch input
L: No SCART
Pin21: I*C Bus (SCL: Serial Clock) *
Pin22: 12C Bus (SDA: Serial Data) *
‘To control TDA91 60, TDA4685, CXA1420P and
NICAM decoder]
Pin23: Load output for DAC (Digital Analogue Converter)
Pin24: TEXT DLIM (out)
Pin25: Clock output for DAC
Pin26: DAC &TEXT Data (out)
Pin27: Ground
Pin28: Not used
Pin29: RESET (in)
Pin30: Oscillator input for CPU (4MHz)
Pin31: Oscillator output for CPU (4MHz)
Pin32: Ground
Pin33: Power ON/OFF (out)
H:Power ON
Pin34: Power error output
H: Normal, H/L switching: Error
Pin35: TVIAV switch 2(out)
Pin36: TV/AV switch 1(out)
Tv AVI AV2 AV3
lPin 35 HLLH
lPin361Hl HILl L
Pin37: SCART 8pin input
Hto L: Switched to AV3
Pin38: Stereo control output 3
Pin39: Stereo control output 2
Pin40: Stereo control output 1
TV mode
Stereo Main(A) Sub(B) Mono Forced Mono
Pin 38 LHLHH
Pin 39 LLHLL
Pin 40 L L HHH
AV mode

Circuit Description
Pin41: Switch for S- VHS (in)
H: S- VHS mode (Y/C separated mode)
Pin42: Skew output
H: Skew ON
Pin43: A2 stereo data input 1
Pin44: A2 stereo data input 2
Stereo Bil. Mono Forced Mono
Pin43 HL L H
Pin44 LHLH
Pin45: Sound mute (out)
Pin46: Line mute (out)
H: Mute ON
Pin47: Option switch scan output 3
Pin48: Option switch scan output 2
Pin49: Option switch scan output 1
Pin50: Key scan output 3
Pin51: Key scan output 2
Pin52: Key scan output 1
Pin53: Key scan input 4
Pin54: Key scan input 3
Pin55: Key scan input 2
Pin56: Key scan input 1
Pin57: OSD (On Screen Display) banking output
Pin58: Not used
Pin59: OSD blue output
Pin60: OSD green output
Pin61: OSD red output
Pin62: Vertical synchronisation pulse input for OSD
Pin63: Horizontal synchronisation pulse input for OSD
Pin64: Power supply (+5V)
3. DAC (IC809) Pin Description —
Pinl: Power supply (+5V)
Pin2: Data input from CPU (Pin26)
Pin3: Clock input from CPU (Pin25)
Pin4: Load input from CPU (Pin23)
Pin5: Surround ON/OFF output
H: Surround ON
Pin6: Not used
Pin7: SIF System(M) output
Pin8: Ground
Pin9: SIF System (1)output
Pinl O:SIF System (B/G, D/K) output
AUTO BIG D/K INTSC4.43
Pin 7LHLHH
Pin 9L L HLL
Pinl OL L I-i HH
Pinl 1: Volume output
Pin12: Surround level output
Pinl 3: Balance output
Pinl 4: Treble output
Pinl 5: Bass output
Pinl 6: Power supply (+5V)
.4
–3–

Block Diagram
L
‘L
IC201 (
drive A
drive B
S-VHS
chrominance
input
S-VHS
luminance
input reference
ing
Composite video input (2
. . ....+/4
Composite video inPU, ~I) -
B
Teletext b
output
SWITCH
PIP output
1ID-1 Chromlflance
JR-y OUtpUt
Filter reference
decouphng
PI I
.uonlvdecouolina_ ~I~i’;fi’ter
Digital
Block Diagram
IC202 (TDA4661 )
ifference
gnals
s
P
L
–4–

Block Diagram
IC203 (TDA4685) Hue control
voItage
M5.MO, #.s.iAse,A65.IW3
SDA
12CBUS -u5x4a--------------------------
...............................,
SCL Ac5.AlxtA15.Am,M.Am, A25.A3U .............................. 1
4,,
m
ISTAND2ND ;
:BREN SWICH-ON
DELAYS
VFE
....................
Leakage and
cut -off
~current input
11’7(
BCOF
1ST,
iES
R
Sandcastle BK 4+
pu15e SANOCASTLE
m,,, or 1)1F&:~mye’
Peak driie
ti I-& limiting
storage
PEAK DRIVE
AND
AVERAGE
BEAM 4
CURRENT
LIMITING
w4
n
3X6 BIT
O/A
CONVERTERS
eAverage
beam current
RI ++@) ,1:
4m
v
I
v
-(R-Y)+
G2-1
I~I
B
SUPPLY
------- 12 Cbusdata and !offstorage
control signals
1
+
Bac
hold
T
A.P. +D.P.
OUT% IN .. ,.
Block Diagram
IC301 (CXAI 420P) ri
APL
.,.
),-output
W%=+k==!i! w
‘m“LA”=x+.J43Cinput cOutmlt Blanking Clamp pulse/
Digital Analogue pulse sand castle pu Ise
greund ground xx
–5–

Service control adjustments
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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 PRECAUTION 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.
(1) Receive the PAL colour bar pattern, (1) Receive the monochrome circular pattern.
(2) Set the brightness and contrast to normal.
g(3) Vertical centering can be adjusted by switching SW501 on
a) gc:
ca~the POWER &DEF PCB ASS’Y.
.= =
$ $ $ 6 g z:pAL colour
bar pattern
x
v:$:
3%
ummca’cen’er
II I I 1I
(2) Connect the oscillator to Q1 33- Emitter on the MAIN PCB
ASS’Y.
(3) Adjust VR131 for 1.OVP- pas shown below.
@
Video det. T
waveform
1
3
0
0
u
o
I.Ovp-p
L
VIDEO
DET, ADJ.
i
❑
~VR131
OQ133
\Emitter
uMAIN PCB ASS’Y
POWER &DEF. PCB ASS’Y
(1) Receive the monochrome circular pattern,
(2) Set the brightness and contrast to normal.
(3) Adjust VR2301 on the SYNC SUB PCB ASS’Y for optimum
horizontal center position.
~orizontal center
(1) Connect the high voltage probe(+) to the anode lead of the
picture tube and the ground.
(2) Receive the monochrome circular pattern.
(1) Receive the monochrome circular pattern.
(2) Set the brightness to normal and contrast to maximum.
(3) Adjust the focus control on the F.B.T for the best focus on (3) Set the brightness and contrast to minimum.
the screen center. (4) The high voltage must be less than 25’’=3OKV, 29’’=32.5
Kv.
– 6 – Note: If the picture tube is replaced, check the high voltage.

Service control adjustments Tuner assembly adjustments
(1) Receive the PAL colour bar pattern.
PAL colour
bar pattern
(2) Connect the oscillator to TP -Y(+) and TP -E( - ) on the
COMB FILTER PCB ASS’Y.
(Oscilloscope sens. ~0.2V/div)
COMB FILTER PCB ASS’Y VR2801
/
\
~02001
00 .......
K78CM
1.. 00
0o
8TP-Y
(3) By using VR2801 on the COMB FILTER PCB ASS’Y,
adjust the amplitude as shown below.
0.05 Vp-p
The following components of Tuner Assembly (645 000 1192) _
can be ordered separately:
Tuner Ass’y (645 0001192)
Ref. No. Part No. Description
AlolA 6450001208 UV Varactor Tuner
IA101B 6450005312 IF Pack 1
+When you order these components together as the Tuner
Assembly, they do not need to be adjusted.
●Since each components is pre -adjusted at the time of
shipment, it does not usually require further adjustment, even
when purchased separately. However, if there is any such
need, you can follow the instructions below to perform the
adjustment.
AGC Adjustment
Note: Do not attempt this adjustment with the weak signal.
(1) Tune the receiver to the most clearest (or strongest) VHF _
station in your area,
Set the brightness and the contrast to maximum.
Set the colour to minimum.
(2) Turn the AGC control (SVR101 )of the IF Pack in direction
which causes the snow to armears, then in opposite
direction until the snow just disappears.
>
0
0
0
Q1
+
BQ133
%AGC Adjustment
MAIN UNIT
–7–

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Adjustments in the Service mode
Since some chassis circuit adjustments are controlled by the CPU built into the chassis, adjustments can now be made
by inputting data directly via the remote control unit supplied with the set.
Memory IC (lC805)replacement
Since adjustment data for the circuit is stored in the memory IC (IC805) that comes with the CPU, the adjustment data
must be re- input when the memory IC is replaced.
(After memory IC replaced, reference data is initially written automatically to memory from the CPU ROM for basic set
operation.)
(1) setting of the service mode.
To enter service mode. mess and hold down the MEMORY key on the front control panel of the TV set, then press the remote
control Normalization key.
~j-- o p F-+ -+
\MEMORY key
(2) Screen display in the service mode.
–Screen display –
ITEM DATA
01.v-s 15
\.
Item o<the ~djustments data
adjustments
A-45=i=-’”i=
AIB SURROUND Fuzzv
‘zw=’8E
~1%~
w
+u.u-&-~
o-J-
Dlm&&
IL’ I
-Normalization
key
(Remote Control Transmkter)
Epy
VPA Prog. UP/DOWN
—LEVEL
}
AIB SURROUND FUZZY
00
●Item of the adjustments can be selected by
pressing Prog. UP/DOWN (7P A )key of the
remote control unit.
.Adjustments data can be set by pressing LEVEL
(-~ +) key of the remote control unit.
See the next page for adjustment items and data.
(3) Reset of the service mode.
To exit from the service mode, turn off the TV set by pressing the Power ON/OFF button of the TV set or the remote control
transmitter.
–8–

Adjustments in the Service mode
The displayed data is not post adjustment data, but initial reference data from the CPU ROM for basic set operation
following memory IC replacement. Perform individual adjustments according to the circuit adjustment method described
earlier when the memory IC is replaced.
–Table of the adjustments –
Screen Display Data
Adjustments Range of a
PAL NTSC data Remarks
01.v-s Vertical Shift Adjustment 31 31 00 – 63 Not used
1
02. V-A Vertical Size Adjustment 34 I34 I00 – 63 I
03. V-L Vertical Linearity Adjustment 31 31 00 – 63
~04. s-c S-Correction Adjustment 31 31 00 – 63
05. H-S Horizontal Center Adjustment 00 00 00 – 63 Not used
06. H-W IHorizontal Width Adjustment I37 I38 I00-63 II
07. P-w Pincushion Adjustment (Parabola width) 28 29 00 – 63
08. C-P Pincushion Adjustment (Corner parabola) 31 25 00 – 63
~09. TRP Pincushion Adjustment 25 I20 00 – 63
10. RRed Gain Adjustment 24 00 – 63
11. GGreen Gain Adjustment 24 00 – 63
12. BBlue Gain Adjustment 24 00 – 63
~13. P-L Peak Drive Limit Adjustment 45 00 – 63
~14. S-L Slice Adjustment 10 00 – 63
~15. S-F Sharpness Focus Adjustment 20 00 – 63
~16. W-H Weighting Adjustment 21 00 – 63
17. C-D Chroma Delav Adjustment 31 00 – 63 Not used
I. . 11,
18. OSD On Screen Display Center Adj. 7 00 – 63
Note: In the event that separate data adjustments are required, such as for PAL and NTSC systems, perform individual
adjustments for PAL and NTSC signal reception.
Adjust for NTSC by inputting the NTSC signal from the AV input terminal.
(1) Connect the oscilloscope to TP -47G and the ground(TE -
47) of the CRT PCB ASS’Y.
(2) Receive the PAL colour bar pattern.
(Set the colour control to minimum and the contrast to
maximum.)
PAL colour
bar pattern
(3) Adjust the brightness control volume to be a=l OV *; V.
Tir
a
T
i’
(4) Set the TV re!%ver to the service mode.
(5) Select”1 1. G“ by pressing Prog. UP/DOWN key.
(6) Adjust so that b=85 Vf3V by pressing LEVEL (- ~ + )key.
Note: This adjustment should be done after sub contrast
adjustment.
(1) Receive the PAL monochrome circular pattern.
(Set the colour and brightness control to normal and the
contrast to maximum.)
(2) Set the TV receiver to the service mode.
(3) Select”1 O. R“ by pressing Prog. UP/DOWN key, and adjust
so that the red gain is optimum level by pressing LEVEL (-
~ + )key.
(4) Select”1 2. Bby pressing Prog. UP/DOWN key, and adjust
so that the blue gain is optimum level by pressing LEVEL
(-~ +)key.
(1) Receive the monochrome circular pattern.
(Set the brightness to normal and contrast to maximum.)
(2) Set the TV receiver to the service mode.
(3) Select “02. V-A by pressing Prog. UP/DOWN key of the
remote control unit.
(4) Adjust the vertical size by pressing LEVEL (- ~ + )key.
–9–