Philips L7.3A Service Manual Download

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Technical specifications

L7.3A

Technical specifications

Mains Voltage:

: 150 - 276 Volt
: 90 - 276 Volt

Mains frequency

: 50 Hz
: 60 Hz

Power Consumption in stand-by

: < 10 Watt

Power Consumption normal mode

: 25” : /- 10%
: 29” : 90 Watt +/- 10%

Chassis mains isolated

: Yes

Aerial input impedance TV

: 75 Ohm - coax

Picture tube range

: 25” and 29”

EHT voltage for 25”

: 27 KVolt

EHT voltage for 29”

: 30 KVolt

Max EHT power

: Linitted at 33 Watt

Sound output power

: 2 X 3 Watt
: 2 X 5 Watt

Picture S/N at 70uVolts

: > 46 dB unweighted
: > 53 dB weigted

Summary of Contents for L7.3A

Page 1: ...cal Diagrams and print lay outs Diagram PWB Main PWB layout 16 Power supply diagram A1 17 16 Main PWB layout 18 Line drive diagram A2 19 18 Sync frame vertical drive diagram A3 20 18 Video Processing diagram A4 21 18 Control diagram A5 22 18 Sound processing diagram A6 23 18 Sound amplifier diagram A7 24 18 BTSC decoding diagram A8 25 18 CRT PWB Audio sound PWB 26 CRT module diagram B 27 26 Nicam ...

Page 2: ...tand by 10 Watt Power Consumption normal mode 25 75Watt 10 29 90 Watt 10 Chassis mains isolated Yes Aerial input impedance TV 75 Ohm coax Picture tube range 25 and 29 EHT voltage for 25 27 KVolt EHT voltage for 29 30 KVolt Max EHT power Linitted at 33 Watt Sound output power 2 X 3 Watt 2 X 5 Watt Picture S N at 70uVolts 46 dB unweighted 53 dB weigted ...

Page 3: ...f panels VIDEO 2 IN ANTENNA IN VIDEO 1 IN OUT VIDEO AUDIO R L AUDIO VIDEO R L CL 86532010_003 ai 160298 Red IR Channel Volume CL 86532010_004 ai 160298 A1 C A2 NICAM PANEL POWER SUPPLY LINE DRIVE SYNC FRAME VERTICAL DRIVE VIDEO PROCESSING BIMOS IC CONTROL A3 SOUND AMPLIFIER BTSC DECODING SOUND PROC SOUND INTERFACE A4 A5 A6 A7 A8 CRT PANEL B MAIN CL 86532010_005 ai 160298 ...

Page 4: ...umstances with higher dust grease or moisture levels for example in a kitchen the recommended interval is 1 year The maintenance inspection contains the following actions Execute the above mentioned general repair instruction Clean the power supply and deflection circuitry on the chassis Clean the picture tube panel and the neck of the picture tube 3 3 Warnings 1 ESD All ICs and many other semicon...

Page 5: ...on with the semiconductors in the unit irrespective of the type indication on these semiconductors Figure 3 2 Figure 3 3 V CL 26532098 042 140792 tuner earth tuner aarde la masse du tuner Tuner Erde massa del tuner tierra del sintonizador with aerial signal met antenne signaal avec signal d antenne mit Antennensignal con segnale d antenna con la señal de antena normal condition normaal bedrijf fon...

Page 6: ...nical instructions For the service position of the main carrier see figure 4 1 The main carrier can be removed by releasing the 2 carrier blocking lips 1 and pulling the carrier panel backwards Figure 4 1 A 2 1 1 1 B CL 86532010_002 ai 160298 ...

Page 7: ...T 3528 3529 5540 6540 Check feedback loop 7581 3577 Check 6445 7445 7518 Check 1500 2507 2508 2517 2529 3510 3518 3519 3521 3525 3529 3530 5545 6514 6540 7518 7520 NO YES YES YES Over voltage protection YES Voltage at pin 14 IC7520 2 5V Check sensing primary CCT 3514 3521 Check 8V supply FM CVBS NO SOUND Voltage 8V 13V 14V OK NO Check 5300 3330 3340 7312 7311 Check 3506 3510 3529 3530 6510 Check 3...

Page 8: ...in red is displayed see Fig 2 REMARKS After the set is in the service mode the short circuit can be removed To leave the Service mode press the stand by button on the remote control REMARKS After switching off and on the mains switch the set remains in the service mode SDM or SAM mode Features are Service settings after entry Service sub menu selection Error buffer display Software version and ide...

Page 9: ...king of the standby LED This is important if no OSD function or picture is available The method is to show that the LED blinks as many as the error code indicates Example Error code 4 will result in four blinks of the LED 0 25 seconds ON and 0 25 seconds OFF After this sequence the LED will be OFF for 3 seconds and the blinking of the LED is repeated again 5 5 5 Option abbreviation and Option stat...

Page 10: ... 6 2 TUNER With the items TUN FAO and TUN FOB the speed time constant for internal signals is set The speed can be set to normal slow or fast The tuner sub menu contains the following information For monitoring during alignment of AGC YD CL IF PLL AFW All entered data will be send directly to the video one chip values are stored in EEPROM if this sub menu is left 4 3 Expend EX ON OFF Games GM ON O...

Page 11: ...lue for all setting is 37 The factory settings of the colour temperatures are DELTA COOL TEMPERATURE SUB MENU DELTA COOL RED 0 DELTA COOL GREEN 1 DELTA COOL BLUE 3 DELTA WARM TEMPERATURE SUB MENU DELTA WARM RED 0 DELTA WARM GREEN 254 DELTA WARM BLUE 249 5 6 4 GEOMETRY The geometry menu contains the following information Into the picture geometry menu the first item will be highlighted and displaye...

Page 12: ...he DST Downloading of tuning data programme number frequency and system via the DST is made possible This downloading is ONLY possible in the version containing PLL tuning for Europe 5 9 Blinking LED procedure Via the DIAGNOSE 1 for errorbuffer position 1 through the DIAGNOSE 5 for error 5 commands of the DST the error buffer can be made visible via the blinking LED This is useful if the screen is...

Page 13: ...7 10 LOCAL KEYBOARD BS 2 BS 1 A4 27 A4 28 A4 13 A6 8 A5 5 VD SDA SCL EEPROM 5 VD REMOTE RECEIVER CHROMA O NTSC SW CHROMA 2 STATUS RESET X TAL 12MHZ B_TXT_OSD G_TXT_OSD R_TXT_OSD FLYBACK A6 15 A7 15 A4 15 A6 16 A7 16 A8 16 A4 16 A4 14 A1 19 A3 20 5V A2 21 A3 21 A4 22 A4 23 A4 24 A4 25 A1 26 M29 M28 SERVICE SAM MODE A8 15 M 25 M 24 SERVICE SDM MODE RC5 A4 18 7620 A6 11 AV MUTE CHROMA 1 BG L A4 17 C1...

Page 14: ...ONTROL A2 LINE DRIVE A3 SYNC FRAME VERT DRIVE A8 BTSC DECODING 200V ANODE CRT FOCUS VG2 HEATER 5V_LOT 5V_LOT HFB PROT 11V_LOT 11V_LOT 48V 29 11V_LOT 11V_LOT X RAY PROT 11V_LOT 5003 EHT VB A4 0 5V div AC 0 1ms div A5 0 5V div AC 0 2ms div A6 5V div DC 10ms div A A7 50mV div AC 0 2ms div A8 50mV div AC 0 2ms div A9 50mV div AC 0 1ms div A19 50mV div AC 0 2ms div A21 50mV div AC 0 1ms div A18 1 2V DC...

Page 15: ... 1V div DC 5ms div A A A C1 5 0V DC F1 0 5mV div DC 5ms div F2 0 5mV div DC 5ms div F3 10V div DC 5ms div F4 10V div DC 5ms div I1 500mV div AC 10µs div I3 1 6V DC I3 4 0V DC I4 5 0V DC I5 0 5 30V DC I7 50mV div AC 500ms div L8 5 0V DC L10 194V DC L9 11 7V DC L2 2V div DC 20µs div 100V div DC 20µs div L1 L3 200mV div DC 10µs div L6 5V div DC 5ms div P2 5V div DC 5ms div P1 270V DC P1 270V DC N2 4 ...

Page 16: ...7 Diagrams and print lay outs 16 L7 3A 7 Diagrams and print lay outs ...

Page 17: ...553 E11 2551 B11 2550 A10 3513 G3 3512 G3 2533 F2 2532 F2 RES RES 150 276 V SINGLE RANGE A5 19 V OPERATION MODE T5AH T5AH 90 276 V FULL RANGE 10V8 A5 26 V STANDBY MODE D C B 2520 E2 2518 C6 2517 C5 2511 C7 2510 B7 2508 B6 2507 B6 2505 B5 2885 A6 SK1 B2 M2 A2 M1 B2 H G 2503 A2 2502 B5 2501 B3 2500 C3 2V6 0V 0V2 2V5 15V1 0V1 2V5 0V 4V9 0V6 8V1 1 12 B A 12 11 7 6 5 4 6 1500 B3 7 A H 2545 H7 2542 C11 ...

Page 18: ...7 Diagrams and print lay outs 18 L7 3A ...

Page 19: ... G H A 9n1 47uH YES 47u 2u2 A3 43 A3 42 0V 82K 0V MTP3055 YES YES 47uH 1mH 10R 14V8 0V1 100R 10R 8 9 10 11 A B A2 1 A2 2 312813851703 312813834021 A2 1 A2 2 BZX79 C9V1 PANEL B CRT 5V6 8V1 7V1 4V9 for ITV purpose 2472 2473 RES RES 9V4 0V B C D M60 G11 2448 E7 2450 B4 2451 B5 2456 F1 9453 YES YES 6461 BYW95C 20 BYW95C 20 1 2 3 4 5 6 7 8 9 10 11 1 2 3 4 5 6 7 BEAMCUR_PROT A5 12 9n1 560p YES TO 34V1 1...

Page 20: ... F9 2405 F7 2407 F7 2408 G10 2420 C6 2422 B5 2425 D5 2426 D5 A5 20 A5 21 A4 33 A2 41 1 2 3 4 5 6 7 8 9 100n 2431 ITEM 3V8 1V3 1V3 2V 3V4 0V4 7V8 2k2 1k8 1k8 6402 10K 3422 F4 1n 2422 2403 100u 680K 3442 1M 3443 3405 3R3 3402 2408 3409 2404 220n 3431 3K3 1R5 7225 D TDA8374C N3 37 40 41 42 43 44 46 47 50 51 52 BAV21 6420 6421 BZX79 C47 7420 BC857B 1n 2440 2441 1n 3441 1K 1K 3440 2 1 7401 TDA9302H FLY...

Page 21: ...9 B4 2211 C3 2212 C3 FOR 2261 E7 2272 C4 2273 C4 2275 C3 2277 C3 2278 D3 2279 D3 G 2 I 1 O 3 4004 6MHZ5 1208 3 2 1 1209 TPS 2 1 TPWA 1207 3 2 1 2 TPS 1206 3 IM39 1 10p 2051 2222 100n 100R 3220 100R 3022 3020 100R 10K 3251 V11 6254 BZX79 C5V1 6260 1N4148 3262 2K2 3261 47K 1N4148 6261 2260 1u 22n 2212 2209 100n 100n 2221 100n 2200 10K 3280 3229 47R 3225 47R 47R 3227 BC857B 7003 3264 220K 5 2013 100n...

Page 22: ...614 9615 3663 680R M24 1 220n 2698 BZX79 F 6650 100u 2651 3653 47K 3651 2K2 3608 47K 4601 2682 27p 8u2 4605 2684 220n 5603 220n 2680 3694 1K8 100n 2694 82p 2622 2621 82p 2603 1u 2K2 2 3657 100R 2K2 3602 B 3 3602 A 3698 1K 3697 820R 10K 3606 3604 3605 10K 4603 10K 6663 LTL 307X 4K7 3667 6661 1N4148 IM33 1 2691 100p 2 3696 1K8 1K8 3695 5601 6u8 5600 2u2 2602 47u 100n 2695 3617 12K 3615 10K 15K 3614 ...

Page 23: ... 2117 G1 2124 E9 2125 E9 B C D E F G H A 4 5 6 5 STEREO A6 1 2 1 12 11 10 M16 G11 0191 G10 1102 G3 1104 G3 1110 G9 1111 H9 1112 B7 1113 C7 1114 C7 1115 B10 1116 C10 1117 C10 1119 E10 470R 3181 212010891663 1K 212010891654 470R SOUND PROCESSING SOUND INTERFACE 1 A7 60 1 2 3 A7 44 8 C 12 A B C D E F G H A B C D E F G H 7 9 10 11 12 1 2 3 12 A B TO C3 4 3 C D 5 6 7 8 9 10 C D 4 3 G H AV_OUT 2 M9 D1 M...

Page 24: ...C5 2321 D5 2322 D5 2323 E2 2324 E2 2325 E2 A B 2328 F2 2329 G2 2351 470n C D E F G H A6 51 A6 52 A6 53 A6 54 2316 C8 2317 C8 2318 C8 1 12 3337 1K 1K 3343 BC847B 7314 470n 2328 2394 470p BC847B 7306 A12 A15 A16 A17 A13 A14 A11 3313 270R 3312 BC847B 7305 1K A23 A25 A22 A20 270R 3365 4318 4323 10u 2308 470n 220R 2315 3324 2358 100n 4314 4312 3330 680R 2338 100u 4K7 3370 4311 10K 3369 3n3 2386 22u 235...

Page 25: ... 3 4 5 6 7 6 5 1 2 3 4 4 5 9 3 2361 C5 2362 C5 2363 C7 2364 C7 2365 E5 2366 E5 2367 E5 2368 E5 E F G H A B C D E F G H 1300 C6 2359 C5 2360 B5 A7 45 A7 46 A5 16 BTSC DECODING A5 15 A6 44 11 12 A B D C 1 2 3 4 5 H E BTSC F G C B A 8 9 10 11 12 A B C D 2380 15n 4317 2368 10u 2369 47n 3351 8K2 3352 150R 3372 47R 1N4148 6304 B1 B2 B3 2359 470n 2361 220n 7 8 9 10u 5301 21 22 23 24 25 26 27 28 29 3 30 3...

Page 26: ...7 Diagrams and print lay outs 26 L7 3A ...

Page 27: ...0 G4 5842 C6 6831 A5 12 A B C D E F G H A C81 GNDLS GNDSS GNDLS Large Signal Ground GNDSS Small Signal Ground PROCESSING DEFLECTION 6833 A5 6835 A6 7830 C2 9840 F4 2845 F6 3831 B5 3832 B6 3833 B5 3834 B6 3835 B5 3836 B6 3840 G4 3841 C6 3842 D6 3845 200VA VG2 3844 22R 1K5 2843 3n3 4R7 3842 7 8 9 C60 C83 10 11 12 1 4 4 5 6 TDA6103Q N3 7830 4 GND 6 VDD 1 VI1 2 VI2 3 VI3 5 VIP 9 VOC1 8 VOC2 7 VOC3 284...

Page 28: ...DA_IN 20 S_DA_OUT 16 S_ID 61 TESTIO1 30 TESTIO2 35 VREF1 27 VREF2 54 VREFTOP 62 XTAL_IN 63 XTAL_OUT 1n 2280 N_CL 23 N_DA 43 PDMC1 44 PDMC2 24 RESETQ 52 SC1_IN_L 53 SC1_IN_R 37 SC1_OUT_L 36 SC1_OUT_R 49 SC2_IN_L 50 SC2_IN_R 34 SC2_OUT_L 33 SC2_OUT_R 46 SC3_IN_L 47 SC3_IN_R 7 STANDBYQ 17 DACM_L 28 DACM_R 64 DMA_SYNC 19 DVSS 18 DVSUP 8 D_CTR_IN 5 D_CTR_OUT0 4 D_CTR_OUT1 21 FRAME 9 I2C_CL 10 I2C_DA 11...

Page 29: ...tment software adjustment Set generator e g PM5418 with colour bar pattern and set frequency for PAL to 189 25MHz and for NTSC 55 25MHz with RF signal amplitudeof 3mv 70dBuv and connect this signal to the aerial input Enter SAM mode by Dealer Service Tool or short circuit service pins M28 and M29 on PCB and switch power ON The menu is displayed whenever SAM mode is entered Enter into TUNER menu se...

Page 30: ... mode is entered Enter into the AUDIO menu and select item according to factory setting Check the sound quality by the generator setting listed below The factory settings for BTSC are Abbriviations ST NT Stereo Nicam adjustment SAP NT Second audio program adjustment LA L L adjustment WIDEB Wideband adjustment SPECT Spectral adjustment NOTE ALL VALUES ARE RECOMMENDED NOMINAL VALUES 8 3 2 2CS NICAM ...

Page 31: ...energy inside the transformer is supplied to the load via secondary windings of T5545 and the secondary diodes D6550 D6560 and D6570 D6590 The current through the secondary side of the transformer decreases with a linear slope of T5545 During T dead FET 7518 does not conduct and no energy is extracted from the mains of supplied side this gives space for T on and T off regulation 9 2 Primary side 9...

Page 32: ... voltage on pin 14 would like to increase which causes V error out to decrease As a result comparator B will give the pulse earlier Vpin 3 will be high for a shorter period shorter T on so the duty cycle decrease and so the secondary output voltages will be decreased corrected This will give a new balance off feedback voltage Vpin 14 and the internal 2V5 reference voltage at a new smaller duty cyc...

Page 33: ...situation the set will switch to low frequency mode or standby mode Whether this unload situation of the SMPS is caused by the standby command or by a failure e g in the line circuitry this can be determined by switching on the set again which the remote control In case of standby mode the TV will switch on again in case of unload situation the set will NOT switch on 9 4 4 Overload short circuit p...

Page 34: ...VBSEXT2 C_EXT2 as inputs which can be selected via the 12C bus Colour Decoder the main functions are PLL VCO The PLL operates during the burst key period It synchronizes the VCXO oscillator with the frequency and phase of the incoming chroma burst For alternating burst PAL standards a loop filter enables the PLL to synchronize with the average burst 180 degrees phase PAL NTSC Identification Secam ...

Page 35: ...mands After the adjustment three RGB black levels are added to the RGB signals These three signals are blanked when the RGB blank signal is active The RGB output stages supply the buffered RGB signals pins 21 20 and 19 Black Stretcher The black stretcher circuit which is only operational during line scan extends the gray signal level towards the actual black level actual black level measured durin...

Page 36: ...y block diagram Output voltage See diagram A2 LOT 5445 Line output transformer output voltage EHT 200V Vg2 focus and ff for the picture tube 200V for the CRT drive 5V for the control and tuner supply 9V for the tuner supply 11V for the control and vertical drive output 11V for the vertical drive output Vertical synchronization IC 7225 5D and the frame amplifier IC 7401 The vertical oscillator 50Hz...

Page 37: ...h an attack time of 16ms and a programmable decay time i e 8 4 2 sec and 20ms IC7311 TDA7057AQ in circuit diagram A7 is a 2X3W stereo sound amplifier Figure 9 1 Vref DEMAGNETIZATION MANAGEMENT CL 56532018 012 080695 reference block supply initialisation block OSCILLATOR THERMAL SHUTDOWN PWM LATCH Set Reset Dmax SOFT START CONTROL UVLO1 Vcc enable Iref OVER VOLTAGE MANAGEMENT BUFFER VC OUTPUT VPIN ...

Page 38: ...ected to the video and audio AV sockets at the back of the TV Switch off the TV and equipment before making any connection Connection for playback VCR VCD 1 Connect to AV sockets connect the corresponding sockets of the equipment to that of the TV to view the playback select a channel named AV1 if connection is made to sockets at VIDEO 1 in or AV2 if connection is made to sockets at VIDEO 2 in Not...

Page 39: ...E SMART PICTURE SOUND h b e y f 4 0 9 to VOL VOL SMART PICTURE SOUND 8 Using the remote control For the remote control to work effectively it has to be operated within the recommended operating range to the remote control sensor on the TV Press Screen information Standby External source Mute Menu Channel selection cursor up or down Result In TV mode Display channel number and sound mode In a menu ...

Page 40: ...STORE 5 Select AUTO STORE with the or key A tuning bar appears and the TV will automatically store all available channels Channels will be stored starting from the next channel number LANGUAGE ENG AUTO STORE B SWAP B LANGUAGE ENG AUTO STORE B SWAP B SKIP B AUTO STORE 15 10 To call up the 1st level menu Press MENU key To use the menus Press the cursor keys scroll up scroll down select or execute To...

Page 41: ...OCK B SURF A CH INSTALLATION B BRIGHTNESS 44 COLOUR 28 13 CHILD LOCK B SURF A CH INSTALLATION B BRIGHTNESS 44 COLOUR 28 installing the tv Manual This menu enables you to search and store every available channel manually 1 Call up 1st level menu with the MENU key 2 Scroll up with the key to highlight INSTALLATION 3 Select INSTALLATION with the or key 4 Scroll down with the key to high light MANUAL ...

Page 42: ...LUME 19 BALANCE O TREBLE 50 VOLUME 30 BALANCE 10 TREBLE 50 BASS 50 INCREDIBLE ST OFF BALANCE 10 TREBLE 40 BASS 50 INCREDIBLE ST OFF AVL OFF GAME VOL VOL CH CH SMART PICTURE SOUND MENU 2 OSD H AV 1 2 3 4 5 6 7 8 9 0 A CH h b e y f 4 SURF SURF A CH INSTALLATION B BRIGHTNESS 44 COLOUR 28 CONTRAST 55 TREBLE 40 BASS 50 INCREDIBLE ST OFF AVL OFF SLEEPTIMER OFF TREBLE 40 BASS 50 INCREDIBLE ST ON AVL OFF ...

Page 43: ...idential code that you have entered when you locked it To set timer 1 Call up 1st level menu with the MENU key 2 Scroll down with the key to highlight SLEEPTIMER 3 Select time period with the or key 4 Exit with the OSD key 20 sound settings AVL Auto Volume Leveller This feature if switched on will automatically adjust any sudden changes in the TV s volume to a preset level 1 Call up 1st level menu...

Page 44: ... the OSD key CODE CHANNEL 5 LOCK YES CODE CHANNEL 5 LOCK NO other features 24 To lock channels 1 Call up 1st level menu with the MENU key 2 Scroll down with the key to highlight CHILD LOCK 3 Press or key to enter menu 4 Key in the universal code 8888 If you do not key in the code you will not be able to change anything on this menu 5 Press or key to select ALL to lock all channels or enter a chann...

Page 45: ...STALLATION B BRIGHTNESS 44 26 other features Surf There are 2 selectable functions 1 Surf Create a list of channels maximum 8 whereby when you press the A CH SURF key on the remote control you are able to quickly view through all these channels 2 A CH When this is selected and if you press the A CH SURF key on the remote control you are able to see the previously watched channel Creating a surf li...

Page 46: ...Green TXT or OSD signal from the uC to IC7225 5C GND Ground GRD_LOT Ground of LOT HOR FLYBACK Horizontal flyback pulse used for looking the horizontal oscillator 12C Digital Control bus of the microcomputer IF Intermediate frequency signal for sound processing INT EXT Switching signal for Internal or external audio video switching L_EXT1 Audio left external 1 LEFT_OUT Audio left out MOD_L_1N1 SCAR...

Page 47: ...200µF 20 25V 2575 4822 126 14087 µF 100nF 10 63V 2601 4822 126 13061 µF 220nF 20 25V 2610 4822 126 13473 µF 220nF 80 20 50V 2615 4822 126 13473 µF 220nF 80 20 50V 2650 4822 126 13482 µF 470nF 80 20 16V 2660 5322 126 10184 µF 680P 5 50V 2661 5322 126 10184 µF 680P 5 50V 2680 4822 126 13061 µF 220nF 20 25V 2684 4822 126 13061 µF 220nF 20 25V f 3171 4822 051 20394 390k 5 0 1W 3178 4822 051 20394 390k...

Page 48: ... 0 5W 3834 4822 117 12516 680Ω 2 0 5W 3836 4822 117 12516 680Ω 2 0 5W 3840 4822 052 10109 10Ω 5 0 33W 3841 4822 052 10108 1Ω 5 0 33W 3842 4822 052 10108 1Ω 5 0 33W 3843 4822 117 11896 1k5 20 0 5W 3845 4822 117 13016 1M A 50V MAX 115V Audio panel ce 7830 4822 209 16321 TDA6107Q N1 1204 4822 242 10769 18 432 000 MHz g 2214 4822 126 13486 µF 15pF 2 63V 2216 4822 126 13061 µF 220nF 20 25V 2217 4822 12...

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