background image

Содержание Magnavox CDB473

Страница 1: ...L AUDIO Chassis CD473 17R Sylvania model CD1473 Chassis CD473 34R CONTENTS 1 Explanatlon subdivision and table of contents per page 2 Controls and technical specifications 3 Servicing hints 4 Measurements and adjustments 5 Exploded views and parts lists of mechanical components 6 Block diagram circuit diagrams PCB data parts lists of electrical components and wiring diagram 7 Changes 8 Additional ...

Страница 2: ...sm Disassembly of CDM Servicing of servo decoder panel Replacement of transformer fuse Electrical measurements and adjustments General checkpoints servicing programme General checkpoints Detailed measuring method Detailed measuring method Detailed measuring method Detailed measuring method Detailed measuring method Detailed measuring method Exploded view tray mechanism Partslist of mechanical comp...

Страница 3: ...closing the disc tray 10 TRACK TIME key for switching from track number to playing time indication and vice versa 11 PROGRAM key for storing the track numbers of a programme and producing the display of the programme stored 12 PAUSE key for holding play at the start of a track or passge and for interrupting play 13 REPEAT key for repeating a disc or a programme 14 J l INDEX I keys for indicating t...

Страница 4: ... fingerprints 4822 397 30096 4822 395 50145 4822 395 50132 4822 53211547 4822 395 30204 4822 322 40066 4822 267 50676 5322 130 32182 Torx screwdrivers Set straight Set square Disc hold down 13th order filter Service cable 14 pole Service connector 14 pole Green LED COYG II cs 9 982 Total harmonic distortion Intermodulation distortion Remote control De emphasis Dimensions wxhxd Weight Headphone Q 0...

Страница 5: ...o do this work the following service aids are available Service flat cable 14 pole 4822 322 40066 Service connector 14 pole 4822 267 50676 These two items should be used to assemble an extension calbe between connector 11 and the flex cable of the CDM 2 unit Remark The service cable should be assembled as follows see drawing MDA 00311 The 14 pole connector should be soldered as indicated in the dr...

Страница 6: ...the set Two screws are situated in front and one in the centre at the rear Lift the tray mechanism a little and undo the flexible PCB from the connector by lifting the upper part of the connector and taking the flexible PCB out Short circuit the connections by means of a papercllp Undo the 2 stocko connectors Now take the tray mechanism out of the set cs 9 983 DEMOUNTING THE CDM Remove the complet...

Страница 7: ...supply voltage The injected levels or signals should never be greater than the supply voltage of the related circuit cs 9 984 4 1 GENERAL CHECKPOINTS In the detailed measuring method below a number of general conditions required for a properly functioning set will not be mentioned Before the detailed measuring method is started these general points should first be checked a Ensure that disc and ob...

Страница 8: ... resistor and the switch serve to draw more current from the laser supply CS 9 939 GB to LO LED GREEN e g CQY 94 IV CONNECTED DIRECTLY TO PANEL 42 444 A12 5322 130 32182 The above circuit is connected to connector 31 via an extension cable instead of a flex print The normal flex print is not suited for this purpose because of its high internal resistance Code no extension cable 4822 322 40066 Take...

Страница 9: ...e should be activity at test point 29 and 31 in position play MSTP pin 20 test point 78 4 3 When after RD high the MSTP is high for a short moment 0 2 sec the turntable motor control will be switched on The turntable motor is controlled by the MC signal test point 12 To check MC see Decoder A IC To check the turntable motor control see CDM2 Service Manual Checking of the motor control BO pin 11 te...

Страница 10: ...position 1 there should be a disc on the turntable cs 9 986 FE pin pin 5 test point 26 The FE signal Focus Error is used to drive the focusing unit When the SI signal goes to high the focal point will be searched for When the player is brought into servicing position 1 without disc the objective will search 1Sx for the focal point At test point 26 the FE signal varies 16x between 2 V and 1 5 V The...

Страница 11: ...that the tracking signals are unreliable Method Can only be used in a playing set Put test disc SA 84822 397 30096 on the turntable Switch on the power supply switch and press the PLAY key Play track number 10 or 15 and check the HFD signal at test point 23 When drop out pulses are present on the DET signal pin 26 the HFD pulses should also be present at test point 23 Position of oscilloscope 2 ms...

Страница 12: ...lter B IC Place a disc on the turntable Select one of the following positions SERVICE POSITION 2 or 3 or position PLAY Trigger the oscilloscope with the WSAB signal test point 71 pin 39 Check signals WSAB at test point 71 pin 39 Word Select from Decoder A to Filter 8 GLAB at test point 72 pin 38 Clock from Decoder A to Filter 8 and their interrelation There must be activity a test point 73 pin 37 ...

Страница 13: ... no 14 recorded without PRE EMPHASIS the DEEM signal should be low During playback of track no 15 recorded without PRE EMPHASIS the DEEM signal should be high VI FILTER B IC Check the signals between Decoder A IC and Filter B IC See sub V Decoder A IC Check the X tal signal Check the timing signals meant for Filter B WSAB CL AB DAAB signals test points 71 72 and 73 Check the EFAB signal test point...

Страница 14: ...nd 6582 test point 92 During playback of track no 15 the analog signal at the source of 6583 test point 91 and 6582 test point 92 should be OV IX KILL CIRCUIT During switching on and off the mains voltage the signal on the collector of 6580 to be measured on a jumper tp93 should be as indicated in the figure below 2V av ois c 1 POWER ON 2V ov X FAVOURITE TRACK SELECT FTS Attention av When repairin...

Страница 15: ......

Страница 16: ......

Страница 17: ...channel Clock signal DODS Drop out detector supression amplified currents D1 and D2 Switch signal aDA a channel Data signal D1 4 Photodiode currents RE dig Radial error digital CEFM Clock Eight to Fourteen Modulator aRA a channel Request Acknowledge FE Focus error signal RE lag Radial error signal for LAG network CLAB Clock signal Decoder A to Filter B SCAB Subcode clock Decoder A to Filter B FE l...

Страница 18: ......

Страница 19: ......

Страница 20: ......

Страница 21: ......

Страница 22: ......

Страница 23: ......

Страница 24: ......

Отзывы: