Dolby Laboratories DA20 Installation Manual Download

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The system alignment procedure is divided into two parts:

The mechanical alignment of the Cat. No. 700 Digital Soundhead.

The electronic adjustment of the DA20 electronics chassis.

UTION

This Installation Manual is for use by qualified personnel only. To avoid electric shock do not perform
any servicing other than that contained in the User’s Manual unless you are qualified to do so.

Summary of Contents for DA20

Page 1: ...MODEL DA20 DIGITAL FILM SOUND PROCESSOR Installation Manual ISSUE 6 Part No 91341...

Page 2: ...n the warranty disclaimer originally shipped with the product and also printed on the back of the invoice Digital decoding covered by the following U S patents 4 790 016 4 914 701 4 799 260 4 941 177...

Page 3: ...ECTION 3 CAT NO 700 DIGITAL SOUNDHEAD ALIGNMENT 3 1 Cat No 700 Digital Soundhead Alignment 3 1 3 2 Test Setup with Oscilloscope 3 1 3 3 Focus Adjustment 3 2 3 4 Exciter Lamp Level Confirmation and Adj...

Page 4: ...ad Maintenance 7 1 7 2 Print Cleanliness 7 2 7 3 Adjustments 7 2 SECTION 8 UNIT SERVICING IN CASE OF DIFFICULTY 8 1 Troubleshooting During the Show 8 1 8 2 Problem Identification 8 2 8 3 Determining S...

Page 5: ...ns 3 units high rack mounting 129 x 283 mm 5 25 in x 19 in Maximum projection behind mounting surface 362 mm 14 25in Shipping Weight 9 kg 20 lb Power Requirements 85 to 265 VAC 50 60 Hz Power Consumpt...

Page 6: ...geover DA20 to Cinema Processor Interface Kit These interface cables connect format control and audio signals from the DA20 to the Cinema Processor Some Cinema Processor types require upgrading to tak...

Page 7: ...No 700 Digital Soundhead 2 The electronic adjustment of the DA20 electronics chassis CAUTION This Installation Manual is for use by qualified personnel only To avoid electric shock do not perform any...

Page 8: ...Vac or 240Vac power source Voltage selection is automatic within the DA20 The switching power supply used in the DA20 may be used with mains voltages in the range 85 265 Vac 50 60 Hz without adjustmen...

Page 9: ...een set to the correct supply voltage and that the correct fuses have been installed To reduce the risk of fire replace the fuses only with the same type and rating Do not use a ground lifting adaptor...

Page 10: ...e di sicurezza Assicurarsi che il selettore di cambio tensione sia posizionato sul valore corretto Assicurarsi che la portata ed il tipo di fusibili siano quelli prescritti dalla casa costruttrice L a...

Page 11: ...plate Part No 67079 KINOTON DP75 FP20 FP30 Order Cat No 696 Adapter Kit plate Part No 67139 Additional plates may become available Consult Dolby Laboratories for availability Mounting the soundhead on...

Page 12: ...Soundhead is to be mounted 5 If an adapter kit is necessary mount the adapter plate to the top of the projector In the case of the Cat No 690 adapter kit the reader attaches to the projector and the...

Page 13: ...th 9 Route appropriate conduit from the audio rack where the DA20 is to be installed to the Cat No 700 Digital Soundhead terminating the conduit at the end of the Digital Soundhead The soundhead has a...

Page 14: ...uit installation Exciter Lamp Power The Cat No 700 Digital Soundhead comes equipped with a 10V power supply to power the internal tungsten halogen exciter lamp This supply is powered via an IEC mains...

Page 15: ...uded for use when a cable is being made up on site The cable should be Belden Datalene 8164 which contains four shielded twisted pairs of computer grade cable with the shields isolated from each other...

Page 16: ...ing with black blue foil covering with black red foil covering with black white foil color may vary depending upon cable manufacturer 5 Install shrink tubing a black 1 2 dia Install 3 inches long over...

Page 17: ...1 8 inches red cut to 2 2 inches black cut to 1 9 inches 8 Strip insulated wires back 12 inch and tin 9 Install 1 16 inch dia clear shrink tubing over each drain wire of the twisted pairs and heat sh...

Page 18: ...if you insert the shortest leads first Wiring table for inserting pins in red Molex connector block Molex pin no Wire color Signal name 1 Black Video 0 2 Shield GND 6 Red 15V 3 Black Video 1 4 Green...

Page 19: ...e link from J9 pin 1 to J9 pin 5 will cause the DA20 to assume that the motor is running constantly allowing automatic switching to analog if required The drawback of a wire link is that the system wi...

Page 20: ...avoid soldering to the backplane of the CP55 Unfortunately this method makes use of the AUX format which will be needed for use by the DA20 Therefore if your theater is equipped with an SRA5 installed...

Page 21: ...ng steps refer to Figure 2 5 11 10 12 CP55 SRA5 TB2 TB1 LT E RT LT E RT 7 8 9 TB1 L E R 7 8 9 out out 15 9 1 J14 8 TB1 TB2 ID7 4 CAT NO 321 ID1 See Figure 2 6 Figure 2 5 SRA5 to CP55 Connections Alter...

Page 22: ...d adhesion of the label to the door Remove the label backing material and carefully position the sticker and press it onto the panel Press it firmly over the entire area to ensure good adhesion 5 Remo...

Page 23: ...n by performing the following tests a Select a non Dolby format 01 for example The SR OUT LED on the SRA5 front panel should be on b Select the 05 Dolby Stereo SR format button The SR IN LED on the SR...

Page 24: ...A20 Rs and SW will have to be soldered directly to the indicated backplane pins of the Cat No 441 As the cable plugs in to the DA20 end of things it will still be possible to disconnect the units from...

Page 25: ...Cat No 441 2 5 1 3 Cat No 441 Control Functions Label The controls on the Cat No 441 are different from those of the Cat No 241 To assist in alignment and prevent confusion we have included a label th...

Page 26: ...6 Ctrl5 S5 7 Ctrl6 S6 60 non sync 8 Ctrl7 S7 10 Dolby Digital 9 n c 10 n c 11 n c 12 GND GND 13 n c 14 Sense0 15 n c 16 n c 17 n c 18 n c 19 n c 20 n c 21 n c 22 n c 23 n c 24 n c 25 C O Status CP55 b...

Page 27: ...e exposed on the backplane and that another slot to the immediate left of the Cat No 150 slot is accessible This second slot and associated connector are for the Cat No 85C Pink Noise Generator Instal...

Page 28: ...t Instructions from the CP65 Manual Action Indication Step No 2 20 0 1 2 3 4 5 6 7 8 9 10 select local remote mute local active auto subwoofer off CAT NO 441 1 2 3 Cat No 441 Subwoofer Alignment 10 Do...

Page 29: ...switch must be in the auto up position at any time the subwoofer system is to function Confirm that the microphone is in the position shown All connections established in the room equalization procedu...

Page 30: ...cut treble gain mag dig opt gain off auto freq cut tp present signal Subwoofer Left Surround Right Surround Cat No 441 Dolby n sync surr gain Q on present signal gnd gain bass Q mid freq cut treble tp...

Page 31: ...level is only an approximation Sound pressure level meters are not appropriate for setting accurate levels of narrow band signals The correct final level will be set later in this procedure using an...

Page 32: ...uto freq cut tp present signal Subwoofer Left Surround Right Surround Cat No 441 Dolby n sync surr gain Q on present signal gnd gain bass Q mid freq cut treble tp bass Q freq mid cut treble gain mag d...

Page 33: ...lay Adjust the cut control so the center of the dip flattens The center of the dip should be at the same level as the skirts Adjust the Q control for the flattest possible frequency response 5 Adjust...

Page 34: ...ual Action Indication Step No 2 26 11 1 12 auto subwoofer off CAT NO 441 13 Cat No 441 Subwoofer Alignment REPEAT 8 10 auto subwoofer off CAT NO 441 04 Dolby Stereo A type 05 1 2 4 8 1 6 3 15 6 3 12 5...

Page 35: ...e locations of the microphone Select format 04 Dolby Stereo A Type Place the Le toggle switch on the Cat No 85C card in the OFF center position and place the C center channel toggle switch in the ON p...

Page 36: ...gain mag dig opt gain off auto freq cut tp present signal Subwoofer Left Surround Right Surround Cat No 441 10 Dolby Stereo Digital Dolby n sync surr gain Q on present signal gnd gain bass Q mid freq...

Page 37: ...he C center channel toggle switch in the ON position Note the change in the average level of the bands from 20 Hz to 100 Hz when the subwoofer switch on the Cat No 441 is switched between OFF and AUTO...

Page 38: ...30 Cat No 441 Surround Equalization Alignment 1 2 OFF RIGHT SURROUND POWER AMP 3 85 dBC STEREO SURROUND 88 dBC MONO SURROUND Dolby gain mono non sync gain points test mono eq Ls R C L Ls R C L gnd Ls...

Page 39: ...r the surround channel then the Ls should be used If more than one surround amplifier is to be used both outputs may be used to feed for example balcony and ground floor The separate level controls an...

Page 40: ...41 Dolby n sync surr gain Q on present signal gnd gain bass Q mid freq cut treble tp bass Q freq mid cut treble gain mag dig opt gain off auto freq cut tp present signal Subwoofer Left Surround Right...

Page 41: ...on the analyzer screen Cat No 441 Surround Equalization Alignment Adjust the Left Surround bass control on the Cat No 441 card for as flat as possible low frequency response on the RTA Use caution wh...

Page 42: ...ut treble tp bass Q freq mid cut treble gain mag dig opt gain off auto freq cut tp present signal Subwoofer Left Surround Right Surround Cat No 441 Dolby n sync surr gain Q on present signal gnd gain...

Page 43: ...d mid equalizer controls interact Repeat the adjustments until no further adjustment is required and you have attained the optimum frequency response Adjustthetreble controlontheCat No 441cardforthebe...

Page 44: ...q cut treble tp bass Q freq mid cut treble gain mag dig opt gain off auto freq cut tp present signal Subwoofer Left Surround Right Surround Cat No 441 ON RIGHT SURROUND AMP OFF LEFT SURROUND AMP Dolby...

Page 45: ...the right surround gain control is located on the Cat No 441 board With the microphone still located at the center of the theatre adjust the Right Surround gain control on the Cat No 441 surround and...

Page 46: ...ep No Cat No 441 Alignment Instructions from the CP65 Manual 2 38 18 bypass switch behind panel NORMAL BYPASS 10 Dolby Stereo Digital Cat No 441 Surround Equalization Alignment 15 NORMAL BYPASS 16 17...

Page 47: ...ar frequency response in the center of the theatre If necessary readjust the left and right surround gains until you are satisfied with the surround to front center balance A large change in the gain...

Page 48: ...CP65 The round cable plugs into J8 on the DA20 and the fanning strip on the other end connects to TB4 as shown Audio from DA20 to CP65 DA20 CP Audio Conn J8 DB25 Male Pin no CP65 TB4 From Digital Ter...

Page 49: ...to Digital feature The DA20 switches to format 05 by holding CTRL2 low for approximately 150ms and returns to format 10 by holding CTRL 4 low for approximately 150ms The CP65 requires about 50ms to sw...

Page 50: ...st be either soldered to or attached to barrier strips on the CP200 control unit backplane See the information supplied with the Cat No 493 card for details on attachment of these wires In order for t...

Page 51: ...droom is particularly useful when the cards are installed in a system using Altec A series loudspeakers or modern loudspeakers with passive crossovers This is because the large treble boost required f...

Page 52: ...ed instead The CP200 output section actually has three signal paths for surround channel signals S P Left surround and Q Right surround In a normal monaural surround installation only the S output is...

Page 53: ...0 Hz low pass filter for the subwoofer in magnetic sound formats The 180 Hz position is intended for installations with no Le or Re speakers where the subwoofer carries all bass track information The...

Page 54: ...igital valid logic signal from DA20 low valid C SK 28 pin S SK28 pin 7 Cat No 517 Grounds pin S to indicate card is in left slot disabling C S channel treble compensation and enabling surround trim po...

Page 55: ...23 23 A B CAT 117 CAT 117 CAT 137 SK18 1 1 23 23 A B CAT 141 JM3 JM3 CAT 160 CAT 150 SP2 emergency c o proj 2 proj 1 B A 23 23 1 1 T A 16 1 SK 13 PJ21 PJ22 PJ23 PJ24 SK 14 SK 15 JM23 JM 24 JM 22 JM21...

Page 56: ...ag no NR Remove the Cat No 141 from slot 37 of the CP200 processor unit first slot in from the right and insert the Cat No 85 Pink Noise Generator in its place Be sure to mute the processor when remov...

Page 57: ...2 51 No text on this page...

Page 58: ...rround EQ Alignment Instructions from the CP65 Manual 2 52 Cat No 441 Surround Equalization Alignment 1 2 OFF RIGHT SURROUND POWER AMP 3 85 dBC STEREO SURROUND 88 dBC MONO SURROUND 04 Dolby Stereo A t...

Page 59: ...or the surround channel then the Ls should be used If more than one surround amplifier is to be used both outputs may be used to feed for example balcony and ground floor The separate level controls a...

Page 60: ...41 Dolby n sync surr gain Q on present signal gnd gain bass Q mid freq cut treble tp bass Q freq mid cut treble gain mag dig opt gain off auto freq cut tp present signal Subwoofer Left Surround Right...

Page 61: ...tem beyond their capabilities simply wastes amplifier power and can result in distortion and possibly damage to the surround loudspeakers Turn the Cut control fully counterclockwise and note the posit...

Page 62: ...ut treble tp bass Q freq mid cut treble gain mag dig opt gain off auto freq cut tp present signal Subwoofer Left Surround Right Surround Cat No 441 Dolby n sync surr gain Q on present signal gnd gain...

Page 63: ...nd mid equalizer controls interact Repeat the adjustments until no further adjustment is required and you have attained the optimum frequency response Adjustthetreble controlontheCat No 441cardfortheb...

Page 64: ...nc surr gain Q on present signal gnd gain bass Q mid freq cut treble tp bass Q freq mid cut treble gain mag dig opt gain off auto freq cut tp present signal Subwoofer Left Surround Right Surround Cat...

Page 65: ...t the right surround gain control is located on the Cat No 441 board With the microphone still located at the center of the theatre adjust the Right Surround gain control on the Cat No 441 surround an...

Page 66: ...p No Surround EQ Alignment Instructions from the CP65 Manual 2 60 18 bypass switch behind panel NORMAL BYPASS 10 Dolby Stereo Digital Cat No 441 Surround Equalization Alignment 15 NORMAL BYPASS 16 17...

Page 67: ...lar frequency response in the center of the theatre If necessary readjust the left and right surround gains until you are satisfied with the surround to front center balance A large change in the gain...

Page 68: ...ng with accessory unit and EQ for P Q channels FROM TO FUNCTION FIGURE REF SK30 pin A Cat No 517 SK28 pin A Cat No 517 optical surround trim VCA signal A SK30 pin M SK28 pin M Cat No 517 Dolby Digital...

Page 69: ...T 117 CAT 117 CAT 137 SK18 1 1 23 23 A B CAT 141 JM3 JM3 CAT 160 CAT 150 SP2 emergency c o proj 2 proj 1 B A 23 23 1 1 T A 16 1 SK13 PJ21 PJ22 PJ23 PJ24 SK14 SK15 JM23 JM24 JM22 JM21 JM9 JM11 JM10 JM4...

Page 70: ...he accessory unit for the first time the surrounds must be equalized Refer to the CP200 Installation Manual page 47 2 5 3 4 Equalization of the Subwoofer Channel Refer to the Cat No 441 alignment inst...

Page 71: ...No text on this page 2 65...

Page 72: ...tion Indication Step No 2 66 0 1 2 3 4 5 6 7 8 9 10 select local remote mute local active auto subwoofer off CAT NO 441 1 2 3 Cat No 441 Subwoofer Alignment from the CP65 Manual 10 Dolby Stereo Digita...

Page 73: ...the auto up position at any time the subwoofer system is to function Confirm that the microphone is in the position shown All connections established in the room equalization procedure apply to the f...

Page 74: ...Subwoofer Left Surround Right Surround Cat No 441 Dolby n sync surr gain Q on present signal gnd gain bass Q mid freq cut treble tp bass Q freq mid cut treble gain mag dig opt gain off auto freq cut t...

Page 75: ...CW position for full cut Cat No 441 Subwoofer Alignment from the CP65 Manual Adjust the mag dig gain control on the Cat No 441 card for a 90 dBC SPL sound pressure level in the theatre If this level c...

Page 76: ...Cat No 441 Dolby n sync surr gain Q on present signal gnd gain bass Q mid freq cut treble tp bass Q freq mid cut treble gain mag dig opt gain off auto freq cut tp present signal Subwoofer Left Surrou...

Page 77: ...er of the dip should be at the same level as the skirts Adjust the Q control for the flattest possible frequency response 5 FROM Adjust the freq control so the center of the dip is in the same band as...

Page 78: ...1 2 4 8 1 6 3 15 6 3 12 5 kHz dB 10 5 0 5 10 CENTER CHANNEL NOTE THIS LEVEL 11 1 12 auto subwoofer off CAT NO 441 13 REPEAT 8 10 auto subwoofer off CAT NO 441 04 Dolby Stereo A type Cat No 441 Subwoof...

Page 79: ...ace the Le toggle switch on the Cat No 85C card in the OFF center position and place the C center channel toggle switch in the ON position Place the subwoofer switch on the Cat No 441 in the OFF posit...

Page 80: ...Left Surround Right Surround Cat No 441 10 Dolby Stereo Digital Dolby n sync surr gain Q on present signal gnd gain bass Q mid freq cut treble tp bass Q freq mid cut treble gain mag dig opt gain off a...

Page 81: ...in the average level of the bands from 20 Hz to 100 Hz when the subwoofer switch on the Cat No 441 is switched between OFF and AUTO There should be a level INCREASE when it is switched to AUTO The sub...

Page 82: ...g S level control on the left Cat No 517 to 85 dBC Select format 04 Dolby Stereo optical and adjust the Opt S surround level control to read 88 dBC on the SPL meter Note This control trims the level o...

Page 83: ...annel note the amplitude on the display Note This is not the same level as observed in step 4 Shut off S1 subwoofer enable on the Cat No 560 to mute the subwoofer output Shut off Center on the Cat No...

Page 84: ...18 S 22 n c 19 blank 22 n c 19 blank 23 n c 20 blank 23 n c 20 blank 24 SW out not connected to JM21 but soldered to pin B1 of SK13 24 n c not connected cut short 25 Spare out not connected cut short...

Page 85: ...RL6 7 GO Button Monitor 8 CTRL7 8 Future 11 A19 of SK27 Soldered 9 N C 9 N C 10 N C 10 N C 11 N C 11 N C 12 GND 12 GND BS23 Pin 5 13 N C 13 N C 14 Sense0 14 Future 8 Pin 14 of SK15 Soldered 15 N C 15...

Page 86: ...L Le level R Re level S P Q level Lo Hi Lo Hi Lo Hi level range level range level range P1 J1 P2 J2 P3 J3 P4 J4 S3 S2 S1 6v 6v mono S gain trim INPUTS C S L Le R Re 10 9 11 S P Q 5 Logic 10 k Fader co...

Page 87: ...none x x x high low low high low low high low low high low low high high low low low low high high A B C C on on off off level range P2 not D D CP50 non SR D CP50 SR D CP200 Fader Rs level P1 Rs leve...

Page 88: ...from Dolby Laboratories as Part No 83306 DA20 Audio Out to CP Conn J8 DB25 Male Pin No CP45 Non Sync Aux Conn J5 Phoenix Male Pin No 1 AGND 4 Com 2 Rs Out 6 Rs 3 AGND N C 4 AGND N C 5 AGND N C 6 AGND...

Page 89: ...tatus 15 Projector C O Format sense and control are accomplished via connection of the CP500 automation lines connected to DA20 CTRL0 through CTRL7 The DA20 monitors the CTRL lines to detect when vari...

Page 90: ...4 AGND 4 Signal Ground 5 AGND 5 Signal Ground 6 AGND 6 Signal Ground 7 AGND 7 Signal Ground 8 AGND 8 Signal Ground 9 AGND 9 Signal Ground 10 AGND 10 Signal Ground 11 AGND 11 Signal Ground 12 AGND 12 S...

Page 91: ...L lines to detect when various formats are selected and asserts Format 10 depending on which mode the DA20 is in In all cases the control lines must be low for a minimum of 80ms to be recognized as va...

Page 92: ...oth edges of the film 3 Check for uneven forces on the rollers or twisting of the film 4 When the path is aligned tighten the soundhead mounting bolts and reel arm 3 2 Test Setup with Oscilloscope The...

Page 93: ...are factory adjusted and should not require adjustment during installation If the soundhead has become misadjusted focusing may be performed Using the setup as above adjust the objective lens CCD asse...

Page 94: ...quire adjustment during installation The procedure for confirming or adjusting the film path follows The flanged guide roller on the top tension arm the spring loaded roller between the sprocket and d...

Page 95: ...be confirmed if the video signal of unobstructed light through the perf hole on the oscilloscope falls in the center of the total CCD video signal To center the video signal on the scope do the follo...

Page 96: ...ion below 4 Tighten azimuth adjustment screws and then refocus the soundhead Verification of synchronization pattern finding The Cat No 671 cards in slots 2 and 3 are responsible for resampling and lo...

Page 97: ...Not Use LEDs will Flash D Do Not Use LEDs will Flash E Do Not Use LEDs will Flash F Do Not Use LEDs will Flash When the CP Type switch is set to one of the Auto Digital Enabled positions the DA20 wil...

Page 98: ...e table below shows representative settings for a variety of common projectors in use Dolby External Digital Readers Projector Delay Projector Delay Ballantyne 35mm 247 Christie 250 Century 35mm SA 24...

Page 99: ...annel and J8 pin 1 signal ground by means of an adapter to monitor the digital audio consult Dolby Laboratories for additional information Stereo Headphones used to adjust sync DA10 CP 4 Adjust SW1 2...

Page 100: ...60 60 60 60 60 60 60 60 60 140 90 80 80 70 70 60 60 60 60 60 60 60 60 150 90 90 80 80 80 70 70 70 70 70 70 70 70 160 100 100 90 90 80 80 70 70 70 70 70 70 70 170 110 100 100 90 90 80 80 80 80 80 80 80...

Page 101: ...image of each interperf area due to the horizontal scanning of the CCD and the vertical motion of the film with respect to the CCD This signal contains the information necessary to reconstruct the 6 a...

Page 102: ...ed The DSP of the System Services card implements a FIFO First In First Out buffer to smooth out the bursts of data from the Error Correction process into a steady stream of data to the Transform Deco...

Page 103: ...o front end can switch to video from the incoming reel prior to the actual picture changeover The changeover to the incoming projector CCD signal will be made at a time after the Motor Start signal eq...

Page 104: ...mode the DA20 will not assert any format commands until Format 10 has been selected In both Auto Digital and Auto Digital Disabled modes after Format 10 has been selected if the DA20 detects a failure...

Page 105: ...th TXD on pin 2 and signal common on pin 7 Pins 4 and 6 are shorted as are pins 7 and 8 to allow direct connection to a standard PC serial port The connector case is wired to chassis ground DA20 J3 DB...

Page 106: ...print and received a mono print in error be sure to check with your local exchange or the film distributor a a a a a a a a a a a a Dolby Digital Print The digital data blocks are clearly visible betw...

Page 107: ...tension is important A proper loop is set when the tension arms match the white half circles The arms must not touch or be too far apart approximately 5mm is correct A C B A C C B B A Set film path so...

Page 108: ...nal levels are displayed for channels Left Right Left Surround Right Surround Center and Subwoofer using four LEDs for each channel The bottom LED in each set shows audio activity less than 40dB below...

Page 109: ...isabled These are described below When the CP Type switch on the DA20 is set to Auto Digital mode for a particular cinema processor type the DA20 will automatically assert Format 10 and switch the Cin...

Page 110: ...the DA20 there are two methods by which to accomplish this First the user can rotate the CP Type switch to position 5 This disables the ability of the DA20 to assert any format commands except those...

Page 111: ...t 10 Format 10 can again be selected from the CP45 CP65 and the DA20 will go into Format 10 To re enable the automatic selection of Format 10 after it has been disabled by pushing the Format 05 button...

Page 112: ...ected without the DA20 forcing the CP200 back into Format 10 If Format 10 is again selected the DA20 will remain in analog reversion mode thus forcing the CP200 to play the analog SR track Auto digita...

Page 113: ...switched after the motor start 6 7 Operation With an Automation System The DA20 may be used in conjunction with any standard automation system but the following guidelines must be followed When used w...

Page 114: ...s of reliable use under normal circumstances Routine replacement will depend on your theater s hours of operation To replace the exciter lamp carefully remove the six screws holding the rear cover pow...

Page 115: ...have no audible effect until the picture quality is degraded beyond use At this point wear may exceed the error correction capabilities of the decoder and switching to the analog track will occur Qual...

Page 116: ...Digital Sound is Lost Switching to the analog track will occur if the Digital Soundhead is playing film which is not in Dolby Digital format or if the digital blocks have become unreadable due to an o...

Page 117: ...rect operation of these signals may be observed by monitoring the Proj1 Motor1 Proj2 and Motor2 LEDs on the front panel of the DA20 5 If Synchronization is Lost Synchronization of the digital soundtra...

Page 118: ...e 8 1 DA20 circuit board locations NOTE In order to comply with FCC regulations the DA20 front panel must be in place and held by all 12 screws during normal operation For troubleshooting ONLY remove...

Page 119: ...ngle LED Block Error which will light whenever an uncorrectable block of data on the film is detected Another single LED Fault above it indicates a fault condition on the System Services board 7 segme...

Page 120: ...anumeric display which allows the DA20 to be switched into various test modes used in manufacture and test The switch should be set to 0 for normal operation Each of the cards in the DA2O has its own...

Page 121: ...If you see C rapidly followed by b before appears on the display the newer versions of the code may have been corrupted and the system has loaded its baseline code In this case any upgrades loaded fro...

Page 122: ...ase fresh copies must be read in from the nonvolatile memory before the system will work again In the DA20 cold booting and warm booting produce slightly different results After a cold boot the system...

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