Philips-MCW-770-Service-Manual(1) 电路图 维修手册.pdf

《Philips-MCW-770-Service-Manual(1) 电路图 维修手册.pdf》由会员分享，可在线阅读，更多相关《Philips-MCW-770-Service-Manual(1) 电路图 维修手册.pdf（77页珍藏版）》请在收音机爱好者资料库上搜索。

1、chapter Technical Specification and Measurement setup .1-2 Location of printed circuit boards.1-5 Warnings ; (play/pause) 172021057 53 (Tuner, CD, Aux) 044 (PC Link) (track / tune) 172021057 31 (Tuner) 33 (CD, Aux) 033 (PC Link) (track / tune) 172021057 30 (Tuner) 32 (CD, Aux) 032 (PC Link) REPEAT N

2、O CODE 20 NO CODE 057 29 (CD) 029 (PC Link) PROGRAM172021NO CODE 122 (Tuner) 36 (CD, Aux) SHUFFLE NO CODE 20 NO CODE 057 28 (CD) 028 (PC Link) DISPLAY1720 NO CODE 057 11 (Tuner, CD) 072 (PC Link) SLEEP1616161638 CLOCK1616161615 TIMER1616161648 TIMER ON/OFF 1616161689 RDS/NEWS1717171715 DIM1616161671

3、 DSC1616161679 VEC16161616107 HOME057057057057141 MUTE1616161613 The RC19532014 uses standard RC5 codes for Tuner- CD- and Aux-mode and standard RC6 code for PC Link-mode. 1-4 TECHNICAL SPECIFICATION 1-5 MCW770 location of pcbs, 31032004 Power Module COMBI BOARD LIGHT BAR LIGHT BAR LIGHT BAR TUNER B

4、OARD MAINS SOCKET WESSLI BOARD PCMCIA WIFI CARD FRONT BOARD HP SOCKET LIGHT WL FRONT BOARD SWITCHES Power Module MAINS BOARD LOCATION OF PRINTED BOARDS 2-1 WARNING All ICs and many other semiconductors are susceptible to electrostatic discharges (ESD). Careless handling during repair can reduce life

5、 drastically. When repairing, make sure that you are connected with the same potential as the mass of the set via a wristband with resistance. Keep components and tools at this potential. f ATTENTION Tous les IC et beaucoup dautres semi-conducteurs sont sensibles aux dcharges statiques (ESD). Leur l

6、ongvite pourrait tre considrablement courte par le fait quaucune prcaution nst prise leur manipulation. Lors de rparations, sassurer de bien tre reli au mme potentiel que la masse de lappareil et enfileer le bracelet serti dune rsistance de scurit. Veiller ce que les composants ainsi que les outils

7、que lon utilise soient galement ce potentiel. d WARNUNG Alle ICs und viele andere Halbleiter sind empfindlich gegenber elektrostatischen Entladungen (ESD). Unsorgfltige Behandlung im Reparaturfall kann die Lebensdauer drastisch reduzieren. Sorgen Sie dafr, da Sie im Reparaturfall ber ein Puls- armba

8、nd mit Widerstand mit dem Massepotential des Gertes verbunden sind. Halten Sie Bauteile und Hilfsmittel ebenfalls auf diesem Potential. WAARSCHUWING Alle ICs en vele andere halfgeleiders zijn gevoelig voor electrostatische ontladingen (ESD). Onzorgvuldig behandelen tijdens reparatie kan de levensduu

9、r drastisch doen vermindern. Zorg ervoor dat u tijdens reparatie via een polsband met weerstand verbonden bent met hetzelfde potentiaal als de massa van het apparaat. Houd componenten en hulpmiddelen ook op ditzelfde potentiaal. i AVVERTIMENTO Tutti IC e parecchi semi-conduttori sono sensibili alle

10、scariche statiche (ESD). La loro longevit potrebbe essere fortemente ridatta in caso di non osservazione della pi grande cauzione alla loro manipolazione. Durante le riparationi occorre quindi essere collegato allo stesso potenziale che quello della massa delpparecchio tramite un braccialetto a resi

11、stenza. Assicurarsi che i componenti e anche gli utensili con quali si lavora siano anche a questo potenziale. Safety regulations require that the set has to be restored to its original condition and parts which are identical with those specified be used. Replace safety components only by components

12、 identical to the original ones. Safety components are marked by the symbol i Le norme di sicurezza estigono che lapparecchio venga rimesso nelle condizioni originali e che siano utilizzati i pezzi di ricambiago identici a quelli specificati. Componenty di sicurezza sono marcati con Veiligheidsbepal

13、ingen vereisen, dat het apparaat in zijn oorspronkeliijke toestand wordt teruggebracht en dat onderdelen, identiek aan de gespecificeerde, worden toegepast. De Veiligheidsonderdelen zijn aangeduid met het symbool s Varning ! Osynlig laserstrlning nr apparaten r ppnad och sprren r urkopplad. Betrakta

14、 ej strlen. Advarsel ! Usynlig laserstrling ved bning nr sikkerhedsafbrydere er ude af funktion. Undg udsaettelse for strling. Varoitus ! Avatussa laitteessa ja suojalukituksen ohitettaessa olet alttiina nkymttmlle laseristeilylle. l katso steeseen ! f Pour votre scurite, ces documents doivent tre u

15、tiliss par des spcialistes agrs, seuls habilits rparer votre appareil en panne. 050704 ESD SAFETY d Bei jeder Reparatur sind die geltenden Sicherheitsvor- schriften zu beachten. Der Originalzustand des Gertes darf nicht verndert werden. Fr Reparaturen sind Bauteile gleicher Spezifikation zu verwende

16、n. Fr Sicherheitsbauteile sind Originalersatzteile zu verwenden. Sicherheitsbauteile sind durch das Symbol markiert. f Les normes de scurit exigent que lappareil soit remis ltat dorigine et que soient utilises les pices de rechange identiques celles spcifies. Les composants de scurit sont marqus CLA

17、SS 1 LASER PRODUCT DANGER: Invisible laser radiation when open. ? After servicing and before returning the set to customer perform a leakage current measurement test from all exposed metal parts to earth ground, to assure no shock hazard exists. The leakage current must not exceed 0.5mA. AVOID DIREC

18、T EXPOSURE TO BEAM. AVAILABLE ESD PROTECTION EQUIPMENT : KIT ESD3 (small tablemat, wristband, connection box,4822 310 10671 extension cable and earth cable) wristband tester4822 344 13999 WARNINGS flag flashes. 3 button pressed? STOP button pressed? N Y 10 PLAY 2; T CD4 CD3 S WL PC LINK KEYKEY CODE

19、2 3 4 5 6 7 8 9 12 15 11 9 (exit) 14 13 16 HOME SOURCE OPEN/CLOSE CD5 CD2 CD1ALBUM - 41 STANDBY-ON ALBUM + 3 KEY STEP IIC 1 IIC 2 IIC 3 IIC 4 IIC 5 IIC 6 IIC 7 IIC 8 IIC 9 IIC 10 IIC 11 IIC 12 IIC 13 IIC 14 IIC 15 IIC 16 IIC 17 exit BASS set to 0dB - BASS ALC=off Tuner, WESSLI board respectively the

20、 CDC module are not switched on in these steps. To check the inputs a signal has to be fed directly to Combi board, sockets 1013, 1022 respectively 1015 AUX0dB0dB-20dB AUX0dB0dB-20dBon on on AUX0dB0dB-20dB AUX0dB0dB-20dB TUNER3)0dB0dB-20dB PC LINK3)0dB0dB-20dB CD3)0dB0dB-20dB AUX+2dB+3dB-20dB AUX0dB

21、+3dB0dB AUX+6dB-6dB-18dB AUX+4dB+1,5dB-18dB AUX step 13 to 17 are intended for factory tests only 0dB0dB-20dB AUX0dB0dB-20dB SOURCEBASSTREBLEVOLUMEISMUTE KEY CODE KEY CODES table 1 KEY - N Y ROTARY ENCODER TEST COMBI BOARD (I2C) TEST VOLUME KNOB turned ccw? Display shows the actual volume level for

22、2s. N Y VOLUME KNOB turned cw? VOLUME XX N Y Display shows Sound ICs are set acc. table 3 Switch to next step acc. table 3 IIC 1 VOLUME XX Y TUNER TEST N Display shows version of tuner board for 3s. DISC 3 button pressed? DISC 4 button pressed? Service Preset-frequencies acc. table 2 are copied to t

23、he RAM. Tuner is normal working except for the PROGRAM button. Volume is set to -20dB. When a Stereo signal is received the stereo flag K will light up. When RDS data are received R.D.S will light up. POWER switched off? N Y Exit Service Testprogram EUR Y Y STOP button pressed? N Y DISC 4 button pre

24、ssed? Last step acc. table 3 reached? N N Display shows the actual volume level for 2s. table 3 3) *To leave Service Testprogram plug mains cord off. *In the main menu the sound settings (volume, .) and trays work as in normal mode. stands for Service mode stands for Version number of the software u

25、sed in the Front (Display) P. To enter Service Testprogram hold 2; again. ADC2 XX Display shows XX = temp. in C 2; button pressed? button pressed? N Y N STOP button pressed? When the value exceeds 138C, the temperature of the set is detected as too high and in turn the set will be switched to Standb

26、y mode. This can also be caused by the Overvoltage Protection circuit, switching the NTC line to ground. 1) 1) e.g. EUROPE FM/MW USA FM/AM OVERSEAS FM/MW 2) To toggle frequency grid hold ALBUM+ 3 it is a dual-frequency oscillator with ceramic resonators 5300 and 5302, which resonate at 500kHz and 42

27、5kHz respectively.The resonators are switched by transistors 7309 and 7316, controlled by the OZ_SW line from the port expander 7406. The reason for 2 frequencies is to avoid tuner disturbances in the AM-band. The oscillator signal is shaped to square wave with 7312-2, afterwards buffered and fed to

28、 the amplifier modulators (ROZ to the right channel, LOZ to the left). One channel gets inverted clock to balance supply loading. Modulator The modulator forms the pulse width modulated signal. For each channel a seperate modulation is required. Power FETs The FETs require drivers which supply the g

29、ates. One for the high-side-FET and one for the low-side-FET. Because of the different supply voltages also an additional level shifter is necessary per driver. Output filter The output filter is necessary to block the 500kHz square wave signal from the speaker. Refers to the left channel in schemat

30、ic diagrams. It consists of a series-mode coil 5101 and a capacity of approx. 550nF (2116, 2134), which forms a Chebycheff filter with 40kHz cut-off frequency at 6 load. For EMC reasons both, the speaker output and the return ground are fed through a common mode coil (5102).The filter is further imp

31、roved by splitting the output capacity into 2116 before and 2134 after the common mode coil. All above mentioned circuitries are located inside the metal shielding box. LF Analog Audio Signal Modulated Digital Audio Signal +VL -VL +VL 0 0 -VL t Duty cycle 9:1 (DC value nearly +VL) Amplitude pos. max

32、. Duty cycle 1:1 (DC value is zero) Amplitude zero Duty cycle 1:9 (DC value nearly -VL) Amplitude neg. max. Class-D Circuit Description (BASED ONPOWER2003 MODULE75-150W CLASSD) V1L+7,5V+AMPV1L+7,5V V1L -37V +5V -45V -37V -45V -AMP-45V OFF ON OFFON Analog Pre-amp. Modulator Driver Power-amp. Level sh

33、ifter Level shifter Square wave Oscillator analog audio signal f= 20Hz .20kHz amplified analog audio signal f= 20Hz .20kHz square wave 500kHz duty cycle 1:1 square wave 500kHz variable duty cycle 0V 5V 0V 5V square wave 500kHz variable duty cycle -45V +52V square wave 500kHz variable duty cycle -45V

34、 +45V square wave 500kHz variable duty cycle -45V -39V output filter Blockdiagram Class D 2002 04 05 Blockdiagram Class D Power 2003 Module (75 - 150W Class D) 11-211-2 Functional Description: Refers to the left channel in schematic diagrams. The first stage of the modulator is an error integrator w

35、hich compares the input to the (24 dB amplified) output signal of the power stage.The difference is leading to a current, which loads the integrator 7122-A.The second stage (7122-B) adds the 500kHz rectangular oscillator signal, creates high gain and low distortion and is again integrating.The outpu

36、t signal leads to a triangle wave form (see oscillogram E).The DC value of this triangle signal is floating, dependent on the amplitude of the analog input signal.The next stage is a comparator, which compares the integrated voltage with the internal switching levels - thus creating a voltage contro

37、lled duty cycle. 7122 C and D improve the shape of the pulses. For details see oscillograms A-F. At pin 8 of IC7122 there is a square wave with the same frequency and duty cycle as the desired output. The next task is to feed this information to the output FETs. Both FETs are n-channel types, so the

38、y are modulated by feeding the gate in respect to the source connection. Inverters 74LV14 are used as drivers.The driver for the low- side FET (7121) is supplied by the negative supply -VL2 and a voltage +VL (generated by 7115 and 6113), which is 7.5V higher than -VL2.The digital signal is level-shi

39、fted by 7128 to the low side driver stage. 3142, 6111 and 2126 together form a delay circuit for rising edges by approx. 100ns for the low side FET. 3154, 6109 and 2137 delay the rising edge by 50ns for the high side FET.This to compensate the switch-off delay of the FETs and ensures that both FETs

40、are not conducting at the same time. The high-side FET (7109) is controlled by the inverted signal taken from pin 2 of 7118, which is level-shifted by transistor 7119.The driver for the high-side FET is supplied by a floating voltage between the amplifier output -V1L and +V1L, created by the charge

41、pump 6110, 2114 regulated by 7114 and 6114 to a 7.5V higher level.The pump is additionally supplied (via 3151) by +45V to ensure supply at start-up (no signal).The last stage in the gate driver consists of three gates in parallel for increased output current for the capacitive load of the FET. For a

42、dditional increase of the switching speed push/pull transistors 7132/7111 are added. Protection Circuits: The amplifier is protected against low load impedance (including short circuit). Current is sensed by shunts 3101, 3130 in both supplies. Overcurrent at the positive supply is then sensed by 710

43、4, the negative supply overcurrent triggers 7117, which then also triggers 7104.The collector current in turn triggers the monoflop 7122-5 and -6, giving a High pulse at pin 10.This shuts off level-shifter 7128 and blocks transistor 7129 and 7131, which draws current into the emitter resistor 3134 o

44、f level-shifter 7119. It is now also shut off. So, both FETs are shut off within approx. 0,2 sec. The monoflop can be reset by: - switching mains off and on again - pressing Standby button and afterwards any source button - plugging headphone in for a short moment When a headphone is used the amplif

45、ier is shut off.This is done by pulling pin 13 of 7122 via signal line AMP_OFF and transistor 7130 to high level.The line AMP_OFF is controlled by the port expander 7406 which detects the headphone via signal line HP_DET. The loudspeakers are protected against DC voltages resulting e.g. from defecti

46、ve FETs.Voltages higher than 2V are detected by 7110 respectively 7112.The transistors conduct and pull the DC_PROT line down, blocking transistor 7243 which in turn disables speaker relay 1201. Adjustments: The gain of the class-D amplifier is 24dB, adjusted by the feedback resistors 3155, 3136, 31

47、49 and the input resistors 3139, 3340.The input reference voltage for 7122-A is approx. half the supply, therefore 3144, 3148 are used for offset compensation.This compensation has to be fine- tuned with trimpotentiometers 3306 and 3307 to obtain 1mV DC output. Service Hints: The analog part of the

48、Combi Board can be repaired without opening the metal shielding box. In case of a Class D problem it is advised to disassemble the board first, desolder the metal bottom cover of the shielding box and assemble the board again.This takes a few minutes only. To de-solder the metal bottom cover proceed

49、 as follows: 1)Remove top cover of shielding box to reduce heat flow 2)Do not use de-solder wick 3)Simply hold the board upright down as shown in picture 1. Heat up solder joints and move tip of soldering iron slowly along the edge of the metal frame. Solder will flow along the soldering tip and rest on the metal plate. A small amount will drop off. A small gap will become visible as indication that the solder connection is released. When all solder joints are released the cover can be