Changhong Electric PF29GA18A Service Manual Download Page 4

SERVICE MANUAL 

4.  When replacing ICs, use specific tools or a static-proof electric iron with small power (below 35W). 

5.  Do not use a magnetized screwdriver when tightening or loosing the deflection yoke assembly to 

avoid electronic gun magnetized and decrement in convergence of the CRT. 

6.  When remounting the TV chassis, ensure that all guard devices, such as nonmetal control buttons, 

switch, insulating sleeve, shielding cover, isolating resistors and capacitors, are installed on the 

original place. 

7.  Replace blown fuses within the TV with the fuse specified in the parts list. 

8.  When replacing wires or components to terminals or tags, wind the leads around the terminal 

before soldering. When replacing safety components identified by the international hazard symbols 

on the circuit diagram and parts list, it must be the company-approved type and must be mounted 

as the original. 

9.  Keep wires away from high temperature components. 

 

PRODUCT SAFETY NOTICE 

CAUTION: FOR YOUR PROTECTION, THE FOLLOWING PRODUCT SAFETY NOTICE 

SHOULD BE READ CAREFULLY BEFORE OPERATING AND SERVICING THIS TV SET. 

1.  Many electrical and mechanical components in this chassis have special safety-related 

characteristics. These characteristics are often passed unnoticed by a visual inspection and the 

X-ray radiation protection afforded by them cannot necessarily be obtained by using replacements 

rated at higher voltages or wattage, etc. Components which have these special safety 

characteristics in this manual and its supplements are identified by the international hazard 

symbols on the circuit diagram and parts list. Before replacing any of these components read the 

parts list in this manual carefully. Substitute replacement components which do not have the same 

safety characteristics as specified in the parts list may create X-ray radiation. 

2.  Do not slap or beat the cabinet or CRT, since this may result in fire or explosion. 

3.  Never allow the TV sharing a plug or socket with other large-power equipment. Doing so may result 

in too large load, causing fire. 

4.  Do not allow anything to rest on or roll over the power cord. Protect the power cord from being 

walked on, modified, cut or pinched, particularly at plugs. 

5.  Do not place any objects, especially heavy objects and lightings, on top of the TV set. Do not install 

the TV near any heat sources such as radiators, heat registers, stove, or other apparatus that 

produce heat. 

6.  Service personnel should observe the SAFETY INSTRUCTIONS in this manual during use and 

servicing of this TV set. Otherwise, the resulted damage is not protected by the manufacturer. 

 
 
 

 

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Summary of Contents for PF29GA18A

Page 1: ...COLOR TELEVISION SERVICE MANUAL MODEL NO CHASSIS NO ETA 1D Please read this manual carefully before service PF29GA18A...

Page 2: ...CT SAFETY NOTICE 2 SAFETY SYMBOL DESCRIPTION 3 MAINTENANCE 3 ADJUSTMENTS 4 SET UP ADJUSTMENTS 4 CIRCUIT ADJUSTMENTS 7 STRUCTURE AND CHASSIS FUNCTION DESCRIPTION 13 STRUCTURE BLOCK DIAGRAM 13 CHASSIS D...

Page 3: ...ICE below 4 Service and adjustment of the TV may result in changes in the nominal EHT voltage of the CRT anode So ensure that the maximum EHT voltage does not exceed the rated value after service and...

Page 4: ...se characteristics are often passed unnoticed by a visual inspection and the X ray radiation protection afforded by them cannot necessarily be obtained by using replacements rated at higher voltages o...

Page 5: ...ts identified by the VDE marking have special safety related characteristics MAINTENANCE 1 Place the TV set on a stable stand or base that is of adequate size and strength to prevent it from being acc...

Page 6: ...t 1 3 Operate the TV for at least 15 minutes 1 4 Degauss the TV set using a specific degaussing coil 1 5 Set the brightness and contrast to maximum 1 6 Counter clockwise rotate the R B low brightness...

Page 7: ...Adjust two tabs of the 6 pole magnet to superimpose red blue line and green line 2 1 6 Remember red and blue movement Repeat steps 2 1 3 2 1 5 until optimal convergence is obtained 2 2 Circumference...

Page 8: ...en the lamp screw holding the deflection yoke assembly Fig 2 4 pole Magnet Movement 6 pole Magnet Movement Center Convergence by Convergence Magnets Incline the Yoke Up or Down Incline the Yoke Right...

Page 9: ...bove steps until the TV is degaussed completely 2 Confirmation and Adjustment for Voltage Caution B voltage has close relation to high voltage To prevent X ray radiation set B voltage to the rated val...

Page 10: ...g the back cover look for the FBT on the main PCB There should be a FCB on the FBT 4 2 Power on the TV and preheat it for 15 min 4 3 Receive a normal TV signal Rotate knob of the FCB until you get a s...

Page 11: ...us data GDET0104 03 Table 3 Function Description for Bus Data Symbol Description Data OSD OSD Horizontal Position 63 OPT Optional Setting B7 RCUT R CUT OFF OPT GCUT G CUT OFF OPT BCUT B CUT OFF OPT GD...

Page 12: ...HITS Hight 60Hz difference from HIT OPT VLIN V Linearity 50Hz OPT PAGE6 VLIS V Linearity 60Hz difference from VLIN OPT VSC VS Correction 50Hz OPT VSS VS Correction 60Hz OPT HBOW OPT HPARA OPT UBLACK 0...

Page 13: ...AUSTP 04 PAGE12 BBCT 06 STBG S TRAP B G 06 STI S TRAP I 08 STDK S TRAP D K 08 STM S TRAP M 05 SSBG S TRAP HP LP B G 08 SSI S TRAP HP LP I 08 SSDK S TRAP HP LP D K 08 PAGE13 SSM S TRAP HP LP M 10 SYNC...

Page 14: ...T DPC OPT DPCS OPT KEY OPT KEYS OPT ECCT OPT PAGE19 ECCB OPT HEHT 04 DPC69 OPT HIT69 OPT TREC 30 TREX 60 VEHT 00 SBY 08 PAGE20 SRY 08 SECD 10 SEC29 00 BASC 40 BASX 70 MODE3 01 BALC 40 FVOL 13 PAGE21 N...

Page 15: ...UCTURE AND CHISSIS FUNCTION DESCRIPTION 1 STRUCTUE BLOCK DIAGRAM 13 Audio Amplifier TMP8897 Video Amplifier H OUT V OUT Power Supply Circuit TUNER AVIN AVIN AVOUT IR KEY Structure Block Diagram for ET...

Page 16: ...AT24C16 for data memory LA78041 for vertical output power amplifying LA42102 for audio power amplifying TA1343N for audio processor FSCQ1265RTYDTU for power circuit adjustment and control The followi...

Page 17: ...a 64 pin shrink DIP package The MCU contains 8 bit CPU ROM RAM I O ports timer counters A D converters an on screen display controller remote control interfaces IIC bus interfaces and the Closed Capti...

Page 18: ...g Italic underline function Two 8 bit internal timer counter 2 ch Conform to CCD REGULATION Time base timer watchdog timer Jitter elimination 16 interrupt sources external 5 internal 11 IIC bus interf...

Page 19: ...SERVICE MANUAL 3 Block Diagram 17...

Page 20: ...o ground shorting to VCC load shorting and overheating Maximum Ratings at Ta 25 Parameter Symbol Conditions Ratings Unit Maximum supply voltage VCC max No signal 22 V Allowable power dissipation Pd ma...

Page 21: ...R 0dBm 40 50 dB Channel separation Sep Rg 10k Vo 0dBm 50 60 dB Muting attenuation ATT Vo 1Vrms BPF 20Hz to 20kHz 80 90 dB VMUTE H Muting on 1 7 3 0 V Muting control voltage The Pin 6 voltage VMUTE L M...

Page 22: ...tput amplifier Input amplifier Input amplifier Vcc ground shorting protection circuit Load shorting protection circuit Thermal protection circuit IN1 IN2 OUT2 OUT1 PWR GND OUT2 OUT1 Ri 30k Ri 30k 1 Ri...

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Page 25: ...y voltage of 24V and output current of 1 8AP P while LA78041 has supply voltage of 30V and output current of 2 2AP P LA78040 LA78041 N602 Vertical Deflection Output Circuit 1 Features Low power dissip...

Page 26: ...Extended Temperature Devices Available 8 lead PDIP 8 lead JEDEC SOIC 8 lead MAP and 8 lead TSSOP Package 2 wire Serial EEPROM AT24C01A 1K 128 x 8 AT24C02 2K 256 x 8 AT24C04 4K 512 x 8 AT24C08 8K 1024...

Page 27: ...ber of other open drain or open collector devices DEVICE PAGE ADDRESSES A2 A1 A0 The A2 A1 and A0 pins are device address inputs that are hard wired for the AT24C01A and the AT24C02 As many as eight 1...

Page 28: ...the 1K requires a 7 bit data word address for random word addressing AT24C02 2K SERIAL EEPROM Internally organized with 32 pages of 8 bytes each the 2K requires an 8 bit data word address for random...

Page 29: ...er Supplies SMPS with minimal external components The PWM controller includes integrated fixed frequency oscillator under voltage lockout leading edge blanking LEB optimized gate driver internal soft...

Page 30: ...IFB VSD TSD Vovp Sync Vocp S Q Q R R 2 5R Vcc good Vcc Drain FB GND AOCP Gate driver Vcc good LEB 600ns PWM Soft start Internal bias Normal operation VBurst Vref Ib Vref Ibufb Burst mode Controller No...

Page 31: ...ted to the inverting input of the PWM comparator The collector of an opto coupler is typically tied to this pin For stable operation a capacitor should be placed between this pin and GND If the voltag...

Page 32: ...GS 1M VDGR 650 V Gate Source GND Voltage VGS 30 V Drain Current Pulsed 2 IDM 36 ADC Single Pulsed Avalanche Energy 3 EAS 950 mJ Continuous Drain Current Tc 25 C ID 5 3 ADC Continuous Drain Current TC...

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