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Akai A-5181 Service Manual
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Akai A-5181 Service Manual

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DVD PLAYER
Model:
A5181
SERVICE MANUAL
www.akai.ru

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Summary of Contents for Akai A-5181

  • Page 1 DVD PLAYER Model: A5181 SERVICE MANUAL www.akai.ru...
  • Page 2 Terminology & Abbreviations Terminology & Abbreviations AC-3 The former name of the Dolby Digital audio-coding system . AC-3 followed AC-1 and AC-2. Still used in some standards documents. Angle In DVD-video, a specific view of a scene, usually recorded from a certain camera angle.
  • Page 3 Terminology & Abbreviations Dolby Digital A perceptual coding system for audio, developed by Dolby Laboratories and accepted as an international standard. Dolby Digital is the most common means of encoding audio for DVD-Video and is the mandatory audio compression system for 525/60 (NTSC) discs.
  • Page 4 Terminology & Abbreviations MP3 MP3 is an acronym for MPEG-1 (or MPEG-2) Layer 3 audio encoding (it is not an acronym for MPEG3). MP3 is a popular compression format used for audio files on computers and portable devices. The compression in MP3 works on the basis of a "psychoacoustic model" which means that parts of the audio that human ears cannot detect are discarded by the encoder.
  • Page 5 Terminology & Abbreviations Title The largest unit of a DVD-Video disc (other than the entire volume or side). Usually a movie, TV program, music album, or so on. A disc can hold up to 99 titles, which can be selected from the disc menu. VCD VCD stands for 'Video Compact Disc' and basically it is a CD that contains moving pictures and sound.
  • Page 6 Terminology & Abbreviations DVD-RAM A recordable format supported by the DVD Forum. It has superior recording features but it is not compatible with most DVD-ROM drives or DVD Video players. It works well when set up like a removable hard disk. DVD-RW DVD-RW is a ReWriteable media format of the DVD-R standard.

  • Page 7: Important Safety Precautions

    SAFETY PRECAUTIONS IMPORTANT SAFETY PRECAUTIONS Prior to shipment from the factory, the products are strictly inspected to conform with the recognized product safety and electrical codes of the countries in which they are to be sold. However, in order to maintain such compliance, it is equally important to implement the following pre- cautions when a set is being serviced.

  • Page 8: Safety Check After Servicing

    SAFETY PRECAUTIONS 7. 1)When a power cord has been replaced ,check that A mark is made on the cord ,under strain ,near the aperture ,and the flexible cord is subjected 100times to a pull of 40N for a duration of 1 second each . 2)During the test ,the cord shall not be displaced by more than 2mm 8.Also check areas surrounding repaired locations .
  • Page 9 SAFETY PRECAUTIONS ·Insulation resistance test confirm the specified insulation resistance or greater between power cord plug prongs and externally exposed parts of the set (RF terminals ,antenna terminals ,video and audio input and output terminals ,microphone jacks ,earphone jacks ,etc .)See table below. ·Dielectric strength test Confirm specified dielectric strength or greater between power cord prongs and exposed accessible parts of the set (RF terminals ,antenna terminals ,video and audio input and output terminals ,microphone...
  • Page 10 SAFETY PRECAUTIONS Measuring Method: (Power ON) Insert load Z between B (earth ground ,power cord plug prongs )and exposed accessible parts .Use an AC voltmeter to measure across both terminals of load Z . See figure and following table . Table 2: Leakage current ratings for selected areas .

  • Page 11: Software Upgrade

    Software Upgrade MTK disc Upgrade Notice 1. The upgrading software must be recorded (burned) on a CD-R or CD-RW disc, and a) Volume ID of the disc must be “MEDIATEK”, in capital letters. All Recording (burning) software supports volume edit. b) The upgrading software must be renamed as “MTK.BIN”, also in capital letters.

  • Page 12: Output Level

    Electrical Performance Standards Test item Requirement Analog output level(V) (Virtual value) 1.0~2.0v 20Hz ±1 125Hz ±1 1KHz ±1 Audio amplitude/frequency response (dB) 10KHz ±1 18KHz ±1 20KHz ±1 Audio SNR (dB) (A) ≥90 Audio distortion and noise (dB) (1KHz) ≤-65 Dynamic Range (dB) (1KHz) ≥80 Cross-Sound base wave (dB)
  • Page 13 Electrical Performance Standards Test item Requirement 1.0±0.2 CVBS output Video Output Level Vp-p(V) 0.3±0.05 Line Sync amplitude ≥250 AV output SVCD ≥350 ≥450 Horizontal Definition (TV) ≥250 S video output SVCD ≥350 ≥500 CVBS ≥3.5 -20dB FEAT Luminance channel bandwidth and Amplitude Response SVCD ≥3.5 -20dB...
  • Page 14 Package (Inbox)and Block Diagrams 1. AV Cable 6. Owner’s Manual bag 2. Batteries 7. Owner’s Manual 3. Remote control 8. EPS 4. scart Cable 9. Power cord 5. Scart cable box 10. Color box...
  • Page 15 DVD Box Block Diagram...
  • Page 16 General Classification of Symptoms Common phenomenon classification VFD no display Check Power line connect to Connect again. Normal? POWER?Check switch ? Check signal wire connect to Connect again, Normal? decoder board correct? KB board OK? To decoder board service D1 To KB board service K1 TV no voice Connect...
  • Page 17 General Classification of Symptoms TV no display Video wire connection correct? Connect to TV correctly Connect again, TV display SCART wire connection correct? normal? Press “v.mode” REMOTE.. Press times, normal? To decoder board service D3\D3-2\D3-3 Cannot open tray Loader too low/high? Adjust loader Check Loader...
  • Page 18 General Classification of Symptoms Do not read disc Disc scratched/dirty? Replace disc Check Loader wire connect to decoder board correct Connect again, normal? Check flat ribbon connect to decoder board correct Connect again, normal? To decoder board service Press “Open/Close” on front panel, the To KB board service K3 data line of KB board has wave out? Press “Open/Close”...
  • Page 19 General Classification of Symptoms Image/voice distortion Disc scratched/dirty? Replace To decoder board service D4, D5 Optical/Coaxial output abnormal Audio setup correct? Adjust according to manual instruction Check optical/coaxial connection to Adjust according to decoder device OK? manual instruction To decoder board service D6 Read disc and halt Disc scratched/dirty? Replace/clean disc...
  • Page 20 General Classification of Symptoms Reading drag To servo board service Cannot operate by remote To KB board service K3 control MIC no voice To MIC service M1 MIC self activated To MIC service M2 Judgment standard for loader damage When below phenomenon exist, the loader may be damaged. 1.

  • Page 21: Power Board Block Diagram

    8-1 Power Board Block Diagram...
  • Page 22 Power Board Block Diagram...
  • Page 23 Main point waveforms and schematic diagrams of electronic components 8-1 Reference waveform of key test point of power board TP1+12V (no disc) 3-mVpp TP1 (reading disc) 250mVpp TP2+5V (no disc) 3-mVpp TP2+5V (reading disc) 40mVpp TP3 (idle) 20Vpp TP3 (no disc)20Vpp TP3 (reading disc)20Vpp...
  • Page 24 Repair of Power Board Power switch working principles TinySwitch-II(TNY267) maintains the simplicity of the TinySwitchtopology, while providing a number of new enhancements tofurther reduce system cost and component count, and topractically eliminate audible noise. Like TinySwitch, a 700 Vpower MOSFET, oscillator, high voltage switched current source,current limit and thermal shutdown circuitry are integrated onto amonolithic device.
  • Page 25 Regulation process of output voltage When the input current of control pin (5) IC2 decreases (or increases), oscillation waveform will be regulated automatically so that T ratio will increase (or decrease) and the output voltage will increase (or decrease). Output voltage feedback circuit is completed by Z1 R8 D13 5 IC2 TNY267 introduction...
  • Page 26 1 No voltage output Measure each output terminal to see Eliminate short-circuit point whether it is short circuit Check a.c. and d.c. conversion Far less than 320V Measure the voltage ofC1 L2 C2 elements such as FUSE, power switch, D1 D2 D3 D4 etc. About 320V Measure the voltage of 5pin (VCC) Open circuit of 1~3 pins of T...
  • Page 27 1. 2 Unstable voltage output, decrease of carrier capability Normal output voltage Other power boards overloaded Take out the output cord, connect false loading Abnormal Abnormal Analyse heating elements Measure the working temperature of elements by infrared thermometer Normal Is the voltage of light-emitting tubes in Replace optical coupling optical coupling at about 1V? Is it normal after replacing Z1?
  • Page 28 COMMON89D_KHM310_V5 MT1389D (LQFP216) DVD Demo Board for KHM310 INDEX & POWER, RESET RF, SERVO & MPEG MT1389E MEMORY - SDRAM, FLASH/EEPROM VIDEO OUT AUDIO DAC WMA8766 NAME TYPE DEVICE Digital 5V SUPPLY DV33 Digital 3.3V MT1389E RFV33 Servo 3.3V MT1389E LDO_AV33 Laser Diode 3.3V AVCC...
  • Page 29 DV33 APLLVDD3 JITFO 390pF J ITFN RFV33 RFVD D3 DV33 RFV33 750k CB10 CE10 2200pF DAC VDD3 0.1uF/N.C 0.1uF 10uF/25v 2200pF 680k A DIN 0.1uF 0.01uF CB11 CE11 330uH 10uF/25v 0.1uF 10uF/25v 2.7u, DIP 10uF/10v 1500pF 150k XTALI 150k PLLVDD3 74HC04 680k DV33...
  • Page 30 SD33 CB36 CB37 CB38 CB39 CB42 CB43 CB40 CB41 CE22 0.1uF 0.1uF 0.1uF 0.1uF 0.1uF 0.1uF 0.1uF 0.1uF C0603 C0603 C0603 C0603 220uF/16V C0603 C0603 C0603 C0603 DC100A MA10 DQ10 MA10 DQ10 SD33 DQ10 DQ10 DBA0 DQ11 DBA0 DQ11 BA/A11 DQ11 BA/A11 DQ11...
  • Page 31 +5VV +5VV R172 75,1% 1N4148 R171 NC L33 1.8uH,DIP CVBS1 CVBS CVBS [5] CVBS1 CVBS1 [5] 3906 +5VV +5VV 1N4148 RESET# RESET# 75,1% MUTE_DAC MUTE_DAC Y[ 3..6] Y[3..6] [ 2 ] 1N4148 [ 2 ] [ 2 ] [ 5 ] +5VV +5VV L32 1.8uH,DIP...
  • Page 32 +12V CE20 R101 MIC_L R102 R103 G / Y 220pF [ 4 ] 10uF/16V B /U [ 4 ] R /V -12V [ 4 ] 1N4148 CE28 A_MUTE R105 U13A R108 R106 [1] A_MUTE CE29 CE27 DAC_ML R107 5.1k 470uF/16V 10uF/16V CVBS 1N4148...
  • Page 33 8-13...
  • Page 34 8-14...
  • Page 35 8-15...
  • Page 36 MTK DECODER MTK1389D decoder board service manual Please check the power supply to decoder board is normal before checking the decoder board. Check the power supply voltage has the normal wave. +5V +12V -12V 3.3V(U2), 1.8V(U1) Check reset circuit (reset at high electrical level) Check crystal circuit (27MHz) and SDRAM frequency (108MHz) Decoder board repair flow chart: (Diagram not included) VFD no output...
  • Page 37 MTK DECODER CVBS no output(audio/tray door normal) Check the video cord connection bad connect correctly good Check video setup (software menu) bad Set to CVBS good Check Q7 emitter voltage between 1.0±0.2VPP (use standard color band signal disc to test) Check Q7 basal pole between 0.4±0.2VPP remove Q7, check PCB Q7 base pole between 0.4±0.2VPP...
  • Page 38 MTK DECODER YUV no output (Audio normal) Check YUV port connected to TV correct Connect YUV Correctly Check video setup to YUV no set to YUV Check Q8, Q10, Q15 emitter voltage between 0.7±0.14VPP Check Q8 Q10 Q15 base pole voltage between 0.1±0.14VPP removeQ8, Q10, Q15, check Q8, Q10, Q15 ReplaceQ8,Q10...
  • Page 39 MTK DECODER VGA video no output (VGA contains R, G, B signal and line/field sync signal. R, G, B signal testing method is the same as YUV Check VGA connect bad Connect correct Good Check DVD system (PAL/NTSC) is the same as TV setting. (In VGA-PAL, line sync frequency is 31250Hz, field sync frequency is 50Hz.
  • Page 40 MTK DECODER SCART video no output Check Scart port connect correct Check DVD player is set to Refer to manual SCART(CVBS/RGB In Scart-CVBS, “RGB-SWITCH” is In Scart-CVBS, PIN167 voltage should be 3.3V high, in RGB, it is 0V. 0-0.4V, in Scart-RGB, it should be 1-3V Check Check MT1389D PIN169 PIN167 voltage good...
  • Page 41 MTK DECODER No 5.1 channel output No Left/Right No Center, No Surround No output Check connection Connection refer to manual good load 1K signal disc, check L37 (left load 1K signal disc, check L39 load 1K signal disc, check L41 channel),L38 (right channel) with (surround left),L40 (surround (center), L42 (subwoofer) with...
  • Page 42 MTK DECODER Servo initial work process Power On System initiated, MT1389D reset and initiated, wait for task Tray door close? Close tray door Pickup in inner circle? Pickup move outward Machine initiated MT1389D Check disc Without disc With disc Auto adjust Wait for order 8-22...
  • Page 43 MTK DECODER Check disc Activate pickup Focus loop move up Focus loop move down Disc check error Focus loop move up Focus loop move down Pickup LD off Initiate auto adjust Action repeat 8-23...
  • Page 44 MTK DECODER Eject tray abnormal (CVBS normal) Check MT1389D Check “TROPEN”, “TRCLOSE” signal level PIN39(TROPEN), normal (When open tray, “TROPEN” should be PIN103(TRCLOSE) high level, “TRCLOSE” should be low level Check “LOAD+”, “LOAD-“ voltage Check IC U3 larger than3.0V (connect multimeter black pen to “LOAD-”, red pen to “LOAD+”...
  • Page 45 Repair of key board 8-25...
  • Page 46 Repair of key board 8-26...
  • Page 47 Repair of key board KB BOARD SERVICE PROCEDURE Power on DISPLAY? Check Power board board connection Connect good correctly Check KB board input power normal Make Power board under normal supply Check SM1694 Replace IC work properly? Replace LED Check other components 8-27...
  • Page 48 Repair of MIC board 6PIN/2.5 -12V +12V MIC1 MIC2 CN401 C407 0.1uF C406 0.1uF +12V E403 100uF/16V E402 100uF/16V PHO401 L401 R401 C403 U401A 4558 3.3uH 0.1uF R409 -12V C402 R403 C401 3300pF 3300pF R407 51k C404 680pF R405 +12V R-VAR1 R417 U401B...
  • Page 49 Repair of MIC board MIC BOARD SERVICE PROCEDURE Microphone Replace microphone, normal? return normal? Connect correct, return MIC signal wire normal? connects decoder board Replace potentiometer, Volume return normal? potentiometer Check Power board and MIC board power Mic board connecting supply normal? wires Replace IC4558, return...