Akai 21CTF66BC User manual

15CTF66BC
21CTF66BC
21CTS65BS
Models:

CONTENTS
1. safety precautions………………………………………………………………………………………2
2. block diagram…………………………………………………………………………………………….3
3．Replacement of memory IC……………………………………………………………………………4
4．Service adjustment……………………………………………………………………………………...5
5．IC’s functional description………………………………………………………………….…………7
6．Test point waveform…………………………………………………………..…………………….…10
7．IC’s voltages………………………………………………………………………………..….……….11
8．Circuit diagram ……………………………………………………………………………………….. 12

.
1.SAFETY RECAUTIONS
2. The design of this product contains special hardware, many
circuits and components specially for safety purposes. For
continued protection, no changes should be made to the
original design unless authorized in writing by the
manufacturer. Replacement parts must be identical to those
used in the original circuits. Service should be performed by
qualified personnel only.
3. Alterations of the design or circuitry of the products should
not be made. Any design alterations or additions will void
the manufacturer’s warranty and will further relieve the
manufacturer of responsibility for personal injury or property
damage resulting therefrom.
4. Many electrical and mechanical parts in the products have
special safety-related characteristics. These characteristics
are often not evident from visual inspection nor can the
protection afforded by them necessarily be obtained by
using replacement components rated for higher voltage,
wattage, etc. Replacement parts which have these special
safety characteristics are identified in the parts list of
Service manual. Electrical components having such
features are identified by shading on the schematics
and by ( ！) on the parts list in Service manual. The use
of a substitute replacement which does not have the same
safety characteristics as the recommended replacement
part shown in the parts list of Service manual may cause
shock, fire, or other hazards
5. Don’t short between the LIVE side ground and
ISOLATED (NEUTRAL) side ground or EARTH side
ground when repairing. Some model’s power circuit is
partly different in the GND. The difference of the GND is
shown by the LIVE: ( ) side GND, ISOLATED (NEUTRAL) :
( ) side GND and EARTH : ( ) side GND. Don’t short
between the LIVE side GND and ISOLATED (NEUTRAL)
side GND or EARTH side GND and never measure with a
measuring apparatus (oscilloscope etc.) the LIVE side GND
and ISOLATED (NEUTRAL) side GND or EARTH side GND
at the same time. If above note will not be kept, a fuse or
any parts will be broken.
6. If any repair has been made to the chassis, it is
recommended that the B1 setting should be checked or
adjusted (See ADJUSTMENT OF B1 POWER SUPPLY).
7. The high voltage applied to the picture tube must conform
with that specified in Service manual. Excessive high
voltage can cause an increase in X-Ray emission, arcing
and possible component damage, therefore operation under
excessive high voltage conditions should be kept to a
minimum, or should be prevented. If severe arcing occurs,
remove the AC power immediately and determine the cause
by visual inspection (incorrect installation, cracked or melted
high voltage harness, poor soldering, etc.). To maintain the
proper minimum level of soft X-Ray emission, components
in the high voltage circuitry including the picture tube must
be the exact replacements or alternatives approved by the
manufacturer of the complete product.
8. Do not check high voltage by drawing an arc. Use a high
voltage meter or a high voltage probe with a VTVM.
Discharge the picture tube before attempting meter
connection, by connecting a clip lead to the ground frame
and connecting the other end of the lead through a 10kΩ
2W resitor to the anode button.
9. When service is required, observe the original lead dress.
Extra precaution should be given to assure correct lead
dress in the high voltage circuit area. Where a short circuit
has occurred, those components that indicate evidence of
overheating should be replaced. Always use the
10. manufacturer’s replacement components.
11. Isolation Check
(Safety for Electrical Shock Hazard)
After re-assembling the product, always perform an isolation
check on the exposed metal parts of the cabinet (antenna
terminals, video/audio input and output terminals, Control
knobs, metal cabinet, screwheads, earphone jack, control
shafts, etc.) to be sure the product is safe to operate without
danger of electrical shock.
11. The surface of the TV screen is coated with a thin film which
can easily be damaged. Be very careful with it when handle
the TV.Should the TV screen become soiled, wipe it with a
soft dry cloth. Never rub it forcefully. Never use any cleaner
or detergent on it.
(1) Dielectric Strength Test
The isolation between the AC primary circuit and all metal
parts exposed to the user, particularly any exposed metal
part having a return path to the chassis should withstand a
voltage of 3000V AC (r.m.s.) for a period of one second.
(…Withstand a voltage of 1100V AC (r.m.s.) to an appliance
rated up to 120V, and 3000V AC (r.m.s.) to an appliance
rated 200V or more, for a periode of one second.)
This method of test requires a test equipment not generally
found in the service trade.
(2) Leakage Current Check
Plug the AC line cord directly into the AC outlet (do not use
a line isolation transformer during this check.). Using a
“Leakage Current Tester”, measure the leakage current
from each exposed metal part of the cabinet, particularly
any exposed metal part having a return path to the chassis,
to a known good earth ground (water pipe, etc.). Any
leakage current must not exceed 0.5mA AC (r.m.s.).
However, in tropical area, this must not exceed 0.2mA AC
(r.m.s.).
●Alternate Check Method
Plug the AC line cord directly into the AC outlet ( do not use
a line isolation transformer during this check.). Use an AC
voltmeter having 1000 ohms per volt or more sensitivity in
the following manner. Connect a 1500Ω10W resistor
paralleled by a 0.15μF AC-type capacitor between an
exposed metal part and a known good earth ground (water
pipe, etc.). Measure the AC voltage across the resistor with
the AC voltmeter. Move the resistor connection to each
exposed metal part, particularly any exposed metal part
having a return path to the chassis, and measure the AC
voltage across the resistor. Now, reverse the plug in the AC
outlet and repeat each measurement. Any voltage
measured must not exceed 0.75V AC (r.m.s.). This
corresponds to 0.5mA AC (r.m.s.).
However, in tropical area, this must not exceed 0.3V AC
(r.m.s.).
This corresponds to 0.2mA AC (r.m.s.)
2

2 Block Diagram
TUNER SAW
EEPROM
TDA111XX
LA78040
E/W H. DRIVE
VIDEO AMP CRT
SOUND AMP
4052
POWER
UNIT
V. DRIVE
IF1 IN
IF2 IN
RF AGC
SDA
SCL
V OUT H OUT
RGB OUT
AUDIO OUT
C IN
S-VIDEO
SPEAKER L
SPEAKER R
V1IN
EHT
DEFLECT
+B
+27V
+12V
+8V
+5V
+3.3V
+13V
-13V
(OPTION)
AN17821
TDA121XX
V1 IN
AL1 IN
AR1 IN
Y IN
U IN
V IN
V OUT
AL OUT
AR OUT
V2 IN
AL2 IN
AR2 IN
LSL OUT
LSR OUT
SELECT V OUT
V IN
U IN
Y IN
V2 IN
AL IN
ARIN
3

4
3. REPLACEMENT OF MEMORY IC
1. MEMORY IC.
This TV uses memory IC. In the memory IC are memorized data for correctly operating the video and
deflection circuits.
When replacing memory IC, be sure to use IC written with the initial value of data.
2. PROCEDURE FOR REPLACING MEMORY IC
(1) Power off
Switch the power off and unplug the power cord from AC outlet.
(2) Replace IC
Be sure to use memory IC written with the initial data values.
(3) Power On
Plug the power cord into the AC outlet and switch the power On.

5
4. SERVICE ADJUSTMENT
4.1 Enter the factory menu
¾PUSH 【MENU】KEY →DISPLAY PICTURE MANUAL → PUSH DIGITAL KEY “6483”→DISPLAY
“B/W BANLANCE”.PUSH 【STANDBY】KEY WILL BE EXIT FACTORY MODE
¾PRESS【TEST】KEY OR【POWER】WILL BE EXIT FACTORY MODE
¾IN【TEST】MODE .PRESS【-/--】KEY WILL BE ENTER【BUS OPEN】.
4.2 Enter the adjustment menu
¾IN “B/W BALANCE” MODE,PRESS【TEST】OR 【CALL】KEY WILL BE ENTER M0.THEN PRESS
【MUTE】KEY WILL ENTER “M1” AND “M2”.
IN “M2” SELECT “SETUP SELECT” TO 1,THEN PRESS 【MENU 】KEY WILL BE ENTER”M3”
TO ”M9
4.3 CHILD LOCK PASS WORD：[4100]
4.4FactoryMENU

MENU0

M0 PAL NTSC DESCRIPTION
TEST.SW 0 Internalsignal
V.SLOPE 25 +00 Picture vertical center(VARIABLE0~63)
V.POSI 23 +00 The vertical positions(VARIABLE0~63)
V.SIZE 32 +00 The vertical amplitude(VARIABLE0~63)
V.SC 32 +00 The Vertical S-correction(VARIABLE0~63)
H.PHASE 35 +00 The horizontal position(VARIABLE0~63)
H.BLK.SW ON Switchofhorizontalwideblanking
H.BLK.L 0 Time of horizontal wide blanking start of
blanking((VARIABLE0~15)
H.BLK.R 0 Time of horizontal wide blanking end of
blanking((VARIABLE0~15)
PROG 0 externalsignal

Receive standard Crosshatch pattern signal for PAL system .
zAdjustv.slopevaluetothehorizontallinejustappearfromhalfbottomshadow.
zAdjustV.posivaluetothecenterhorizontallinecorrespondtoCRTverticalcenter

zAdjustV.sizevaluetoget90%ofverticalpicturecontentswouldbedisplayedonCRT
zAdjustVSCvaluetoverticalS-correctionisok
zAdjustH.PHASEvaluetogetthepicturehorizontalcentercorrespondtoCRThorizontalcenter







MENU1

 
 
 
 
 
 
 
 

M1 PRESET DESCRIPTION
TEST.S 0 0=external signal,1=black signal ， 2=white
signal ， 3=red signal ， 4=green signal,5=blue
signal
R．BIA 32 R bais adjusted(VARIABLE0~63)
G．BIA 32 G bais adjusted(VARIABLE0~63)
B．BIA 32 B bais adjusted(VARIABLE0~63)
R．DRV 32 Rdrive adjusted(VARIABLE0~63)
G．DRV 32 G drive adjusted(VARIABLE0~63)
B．DRV 32 B drive adjusted(VARIABLE0~63)
SUBBRT 32 Sub Brightness (VARIABLE0~63)
VSD  Verticalscandisable
CL 12 Cathodedrivelevel(VARIABLE0~15)
BLOC 6 Blackleveloffsetcourse(VARIABLE0~15)

zSELECTTHESIGNALINʻʻTEST.SʼʼMENU
zSELECTʻʻVSDʼʼANDPRESSʻʻV+ʼʼKEY.WILLBEENTERSCLINEMODE
zPRESSNO.ʻʻ2ʼʼISREDUCEʻʻR．BIAʼʼANDNO.ʻʻ3ʼʼISINCREASEʻʻR．BIAʼʼ
zPRESSNO.ʻʻ4ʼʼISREDUCEʻʻG．BIAʼʼANDNO.ʻʻ5ʼʼISINCREASEʻʻG．BIAʼʼ
zPRESSNO.ʻʻ6ʼʼISREDUCEʻʻB．BIAʼʼANDNO.ʻʻ7ʼʼISINCREASEʻʻB．BIAʼʼ
6

7
zWHENTHEWHITEBANLENCEISOK，AJUSTG2VOLTAGETOTHESCREENJUST
DISPLAYTHELINE
zPRESSV+KEYWILLBEEXITTHESCLINEMODE


MENU2
M2 PRESET DESCRIPTION
RF.AGC 29 RF AGC (VARIABLE0~63)
OSD.V.POS 21 16 Vertical position of OSD（0~63）
OSD.H.POS 43 18 Horizital position of OSD（0~15）
OSDBRT 15 AdjustbrightnessofOSD
SHIPPING  Shippingmode
SETUPSELECT 0 Theitemsetuptoʻʻ1ʼʼandpressmutekey
willbeenternextmenu
zReceive 60dBu (1mv)VH color bar signal，adjust AGC value（voltage from high to low）to
picture noise reduce gradually to be just disappeared. Select “shipping”, push [V+] [V-]key to
be shipped.
5. IC’s functional description

TDA111XX&TDA121XXFunction : Main IC
SYMBOL PIN DESCRIPTION
IFVO 1 CVBSoutput(front-endorselectedvideo)
VP2 2 SupplyVSP(IFandsound)--(5V)
VCCAUDIO 3 SupplyVSP(onlysoundoutputstage)--(8V)
PLLIF 4 IF-PLLtime-constant
GND2 5 GroundVSP(IFandsound)
DECSDEM 6 Demodulatordecouplingcapacitor
FMDEMOUT 7 AVL capacitor,second sound IF output or
demodulatedsoundoutput
EHTO 8 EHTfeedbackinput
AGC 9 TunerAGCcontroloutput
IREF 10 Currentreferencecomponent

8
VSC 11 Verticalsawtoothcapacitor
IFIN2 12 VideoSAWfilterinput2
IFIN1 13 VideoSAWfilterinput2
VDRA 14 VerticaldriveoutputA
VDRB 15 VerticaldriveoutputB
AVL/EW 16 CapacitorforautomaticvolumelevelingorE/Wdrive
output
DECBG 17 Bandgapdecoupling
SECPLL 18 SECAM-PLLoscillator
GND1 19 Ground VSP(chroma processing and sync and
geometry)
PH1LF 20 AcquisitionPLLfirstphaseloop
PH2LF 21 Secondphaseloopcomponents
VP1 22 SupplyVSP(5V)
DECDIG 23 Digitaldecoupling.
XTALOUT 24 24.576MHZcrystaloutput
XTALIN 25 24.576MHZcrystalinput
IR 26 IRreceiver
MUTE 27 MUTEoutput
S-INDENT/UFH 28 S-VIDEOindent
KEY 29 Keyinput
BAND2 30 BAND2
BAND1 31 BAND1
TUNING 32 14BITPWMVToutput
VDDP 33 SupplyTCGperiphery(3.3V)
SDA 34 SDA output
SCL 35 SCL output
AV1 36 AV1control
AV2 37 AV2control
STANDBY 38 Standbyoutput
50/60HZ 39 50/60HZcontrol
VDDC 40 SupplyTCGcore(3.3V)
GND5 41 GroundTCGanddigitalgroundVSP
VPE 42 OTPprogrammingvoltage
VDDA 43 AnalogsupplyTCGdigitalsupplyVSP(3.3V)

9
BOUT 44 Blueoutput
GOUT 45 greenoutput
ROUT 46 Redoutput
BLKIN 47 Feedbackinputcontinuouscathodecalibrationloop
andverticalguardinput
BCLIN 48 Averagebeamcurrentlimiterinput
PB 49 Pbinput
Y3/CVBS3 50 YCVBSorY(C)input
PR/C3 51 Crinput
YOUT 52 Youtput
YSYNC 53 Inputsyncseparator
VP3 54 SupplyVSP（5V）
GND3 55 GroundVSP
HOUT 56 Horizontaldeflectionlinedriveoutput
FBISO 57 Flybackinandsandcastleout
LSR 58 Audiooutput(loudspeakerright)
LSL 59 Audiooutput(loudspeakerleft)
C2/C3/C4/AIN5R 60 Chromaoraudioinput
AIN3/IN1R 61 Audio1input
CVBS2/Y2 62 CVBS2input
AIN2/1INL 63 AUDIO2input
CVBS/Y4/AIN5L 64 CVBS1input

AN17821/17823 Function : audio output
Symbol PIN Function Symbol PIN Function
Vcc 1 Power supply GND 7 ground
Out 1 (+) 2 Ch 1 output (+) In 2 8 Ch 2 input
GND(out 1) 3 Ch 1Ground VOL 9 Volume Control
Out 1 (-) 4 Ch 1 output (-) Out 2 (-) 10 Ch 2 output (-)
Standby 5 Mute input GND(out 2) 11 Ch 2 Ground
In 1 6 Ch 1 input Out 2 (+) 12 Ch 2 output (+)
Note: AN17823 is pin 1 to 9, AN17821 is pin 1 to 12.
STV9302A /LA78040 Function : vertical output
Symbol PIN Function Symbol PIN Function
INV IN 1 Input V OUT 5 Vertical output

VCC1 2 Power VCC2 6 Output power supply
PUMP UP 3 Pump up power NON INV IN 7 Negative feedback
GND 4 Ground
6. Test point Waveforms
10
TDA111XX PIN44
1.2Vpp
1.2Vpp1.2Vpp
H
H
H
TDA111XX PIN45 TDA111XX PIN46
1.3Vpp
TDA111XX PIN24
2.0Vpp
H
TDA111XX PIN1 0.9Vpp
V451 C
5Vpp
1000Vpp
H
H
1Vpp
V
H
H
CRT KB
CRT KGCRT KR
95Vpp
95Vpp95Vpp
H
H
H
TDA111XX PIN56
TDA111XX PIN57
HEATER
22Vpp
H
0.8Vpp 2.7Vpp
V
V451 B
TDA111XX PIN15
TDA111XX PIN14

11
7. IC’s voltages
TDA111XX/TDA121XX
PIN 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
V 1.5 5 8 2.0 0 2.2 2.6 2.2 1.3 2.0 2.4 1.9 1.9 0.7 0.7 0.4
PIN 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32
V 2.3 2.3 0 2.3 1.8 5 2.6 1.8 1.8 5 0 0 3.3 0 0 -
PIN 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48
V 3.3 3.8 3.6 0 0 3.3 0 3.3 0 0 3.3 2.2 2.2 2.2 0 2.6
PIN 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64
V 0.5 1.4 1.6 1.6 1.9 5 0 0.6 0.35 2.5 2.5 0.6 2.2 1.4 2.2 1.4
STV9302A/LA78040
PIN 1 2 3 4 5 6 7
V 0.7 15 -12 -15 0.3 15.9 -0.07
AN17821/AN17823
PIN 1 2 3 4 5 6 7 8 9 10 11 12
V 12 7 0 7 3.3 1.4 0 1.4 0 7 0 7