Akai 21CTU91BC Service Manual
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Akai 21CTU91BC Service Manual

Crt color tv set
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CRT COLOR TV SET
21CTU91BC

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Summary of Contents for Akai 21CTU91BC

  • Page 1 CRT COLOR TV SET 21CTU91BC...
  • Page 2 SERVICE MANUAL AKAI 21CTU91BC This manual is the latest at the time of printing, and does not include the modification which may be made after the printing, by the constant improvement of product...

  • Page 3: Table Of Contents

    - Content ......................... 2 - Bill of Materials ......................3 - Safety Precautions ....................... 7 - TV Block Diagram ......................8 - Replacement Of Memory IC ..................10 - Service Adjustment ...................... 10 - ICs Functional Description ..................18 - Test point Waveforms ....................22 - Purity / Convergence Adjustment ................

  • Page 4: Bill Of Materials

    PCB NO. SER DESCRIPTION CABLE & SOCKET AV6-14 XS801 CH5B-2.5-2DY XS601 XS602 XS702 CH5B-2.5-4DY XS403 XS703 XS704 XS804 CH5B-2.5-5DY XS201 CH7-10-1DY CH7-10-2DY XS501 XS502 CH7-8-10-4DY XS402 CH9-2.5-2DY-400-CH5B 卧式 XS703 XS704 CH9-2.5-4DY-400-CH5B 立式 XS701B 10 CH9-2.5-4DY-400-CH5B-4(带屏蔽) XS702B 11 CH9-2.5-4DY-450-CH5B XP902 12 CH9-2.5-4DY-550-CH5B PA102 13 CH9-2.5-5DY-500-CH5B XP901...
  • Page 5 SER DESCRIPTION QTY PCB NO. 66 RT-1/6W-5.1KΩ-J R414 67 RT-1/6W-680Ω-J R202 68 RT-1/6W-680Ω-J R707B 69 RT-1/6W-680Ω-J R719B 70 RT-1/6W-8.2KΩ-J R702B CERAMIC CAPACITOR 71 CT-1KV-1000pF-K(湿封装） C504 C505 72 CT-2KV-1000pF-K C943 73 CT-2KV-471pF-K C553 74 CT-2KV-680pF-K C513 C511 75 CT-500V-1000pF-K C452 76 CT-500V-3900pF-K C451 C510 77 CT-63V-0.01uF-Z...
  • Page 6 SER DESCRIPTION QTY PCB NO. 133 STV9325/STV8172A N301 134 TC4052/HEF4052BP N801 135 TDA7266SA N601 136 TL431 V551 137 UPC574/KA33V N561 JUMPERS W214 W216 W402 W504 W505 W509 W510 W563 W591 W602 138 10MM W701 W702 W704 W712 W801 W802 W803 W804 W805 W806 L901 139 12.5MM...
  • Page 7 SER DESCRIPTION QTY PCB NO. SCREWS 193 2.0 X 3.5MM L441(短孔2) T501(4) T401(3) 194 2.3 X 3.5MM C507(2) 195 TR 3×10 (without pad) N301 N502 V451 196 TR 3×10 (with pad) V303 N601(2) TACT SWITCH 197 KFC-A06-P5 TRIODE 198 2SA1015-Y V563 V601 V803...

  • Page 8: Safety Precautions

    SAFETY PRECAUTIONS The design of this product contains special hardware, many 10. Isolation Check circuits and components specially for safety purposes. For (Safety for Electrical Shock Hazard) continued protection, no changes should be made to the After re-assembling the product, always perform an isolation original design unless authorized in writing by the check on the exposed metal parts of the cabinet (antenna manufacturer.

  • Page 9: Tv Block Diagram

    TV Block diagram TDA11105-XXXX video IF IN R IN TUNER RF AGC B IN video video CHROMA AR i1 4052 VIDEO CVBS/Y IN ALi 1 Video IN CVBS1 IN 24C08 CVBS2 IN ARi 2 MA IN L ALi 2 MAOUTR MA IN R MAOUTL RGB OUT...

  • Page 11: Replacement Of Memory Ic

    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.
  • Page 12 production doesn't need to carry on M 3~ adjustments of M9. In "M0"~under"M9" appearance press” CALL” the key can get into "M" appearance. At “M”under the appearance press “-/-“ the key can get into “BUS OPEN” appearance, at “BUS OPEN under, press “-/-“...
  • Page 13 C standard UOC for export bus control adjustment item default setting 2007-12-05 Items Variable Preset recommendation 50HZ 60HZ 50HZ 60HZ V. LOPE +/-32 Picture vertical center adjustment V. SIZE +/-32 Vertical amplitude adjustment V. SC +/-32 Vertical S Correction Adjustment V.LINE +/-32 Vertical positions adjustment...
  • Page 14 0~63 Cut-off control range 0:normal control range 1:extended control range CHINESE ON/OFF OSD language selection THAI ON/OFF OSD language selection VIETNAM ON/OFF OSD language selection INDONESIA ON/OFF OSD language selection ARABIC ON/OFF OSD language selection Vercital amplitude System I output signal amplitude correction 0:no correction 1:amplitude + 12% Control sequence of beam current limiting 0:normal operation(contrast—brightness)
  • Page 15 DCXO Crystal load electric capacity compensate Forced slicing level for vertical sync Slicing level for horizontal sync separator 0:50% 1:30%,direction top sync Group delay on CVBSI signal 0:no group delay correction 1: group delay correction switched on Sync hronization of OSD/TEXT display ON/OFF Black current stabilization Disable flash protection from deflection timer...
  • Page 16 DSGLS Extra gain selection loudspeaker outputs 0:+0 Db 1:+6 Db No red reduction during blue stretch AMLOW Audio output signal for AM sound GSSIF Extra gain-range SSIF for AM demodulation V.P1 0~100 V.P1 volume of VALUE V.P25 0~100 V.P25 volume of VALUE V.P50 0~100 V.P50 volume of VALUE...
  • Page 17 M.COLOR 0~100 mild Color in pp mode M.SHARP 0~100 mildSharpness in pp mode W.BRT 0~100 factory adjusts Brightness W.CONT 0~100 factory adjusts Contrast W.COLOR 0~100 factory adjusts Color SC BRT 0~100 Subsidiary Bright Adjustment COOL 0~63 Cool color adjustment WARM 0~63 Warm color adjustment ON/OFF...
  • Page 18 4 , LOGO EDIT This software LOGO is a pair of pleased words and customer to edit 2 kinds, at the M_MODE, long press[P.P]the key can get into a pair of pleased words editor appearance. ( Operate Press[1]/[2] keys: The LOGO perpendicular position adjust, [1] adjusts upward, [2] get down adjustment;...

  • Page 19: Ics Functional Description

    ICs functional description UOC TDA11105-XXXX/TDA11106-XXXX SYMBOL DESCRIPTION IF VO IF video output / selected CVBS output Supply voltage TV processor(+5v) VCC AUDIO 8 volt supply for audio switches(+5V~8V) PLL IF IF-PLL loop filter GND2 Gaound 2 for TV processor DECSDEM decoupling sound demodulator or SIF input 2 FMDEMOUT audio output /AM audio output (volume controlled)
  • Page 20 VDDC Supply(3.3V) GND5 Ground 5 OPT programming Voltage VDDA Supply voltage(3.3V) BOUT Blue output GOUT Green output ROUT Red output BLKIN black current input / V-guard input BCL IN beam current limiter input B input / U (B-Y) input / P input Y3/CVBS3 G input / Y input...
  • Page 21 BLOCK AND APPLICATION DIAGRAM TDA7266SA V CC 470µF 100nF 0.22µF OUT1+ S-GND OUT1- Vref 0.22µF OUT2+ OUT2- PW-GND D94AU175B ABSOLUTE MAXIMUM RATINGS y l l Total Power Dissipation (T ° 0 ° ° stg, THERMAL DATA ° th j-case ° th j-amb ELECTRICAL CHARACTERISTCS = 11V, R...
  • Page 22 Ω Mute Threshold for V > 6.4V; Vo = -30dB MUTE for V < 6.4V; Vo = -30dB -075 -0.5 ST-BY µA ST-BY Total Output Voltage A Curve; f = 20Hzto 20KHz µV Distortion vs Frequenc Gain vs Frequency Le vel(dB r) THD(%) 5.0000 4.0000...

  • Page 23: Test Point Waveforms

    LA9302A/8177/LA78041/LA78040 Function : vertical output Symbol Function Symbol Function INV IN Input V OUT Vertical output VCC1 Power VCC2 Output power supply PUMP UP Pump up power NON INV IN Negative feedback Test point Waveforms 1.2Vpp 2.6Vpp 3.8Vpp 2.5Vpp 2.5Vpp TDA11105 PIN45 TDA11105 PIN44 TDA11105 PIN46...

  • Page 24: Purity / Convergence Adjustment

    PURITY / CONVERGENCE ADJUSTMENT PURITY ADJUSTMENT WEDGE Demagnetize CRT with the demagnetizer. DEFLECTION YOKE Loosen the retainer screw of the deflection yoke. Remove the wedges. Input a green raster signal from the signal generator, and turn the screen to green raster. Move the deflection yoke backward.
  • Page 25 STATIC CONVERGENCE ADJUSTMENT 1. Input a crosshatch signal. 2. Using 4-pole convergence magnets, overlap the red and blue lines in the center of the screen (Fig. 1) and turn them to magenta (red/blue). (FRONT VIEW) 3. Using 6-pole convergence magnets, overlap the magenta (red/blue) and green lines in the center of the screen and turn them to white.

  • Page 26: Explore View Diagram

    21CTU91BC...

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