Akai A-5181 Service Manual

DVD PLAYER

Model:

A5181

SERVICE MANUAL

www.akai.ru

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. Different angles can be chosen while viewing the scene.
CD Short for compact disc, an optical disc storage format developed by Philips and Sony.
CD-DA Compact disc digital audio. The original music CD format, storing audio

information as digital PCM data. Defined by the Red Book standard.
CD+G Compact disc plus graphics. A variation of CD which embeds graphical data in with

the audio data, allowing video pictures to be displayed periodically as music is

played. Primarily used for karaoke.
CD-R An extension of the CD format allowing data to be recorded once on a disc by using

dye-sublimation technology. Defined by the Orange Book standard.
Channel A part of an audio track. Typically there is one channel allocated for each

loudspeaker.
Chapter In DVD-Video, a division of a title. Technically called a part of title (PTT).
Closed Caption Text captions for video which are not normally visible, as opposed to open

captions, which are a permanent part of the picture. In the United States, the official

NTSC Closed Caption standard requires that all TVs larger than 13 inches include

circuitry to decode and display caption information stored on line 21 of the video

signal. DVD-Video can provide closed caption data, but the subpicture format is

preferred for its versatility.
Component Video A video system containing three separate color component signals, either

red/green/blue (RGB) or chroma/color difference (YGbCr, YPbPr, YUV), in analog

or digital form. The MPEG-2 encoding system used by DVD is based on

color-difference component digital video. Very few televisions have component

video inputs.
Composite Video An analog video signal in which the luma and chroma components are

combined (by frequency multiplexing), along with sync and burst. Also called CVBS.

Most televisions and VCRs have composite video connectors, which are usually

colored yellow.

CD-i Compact disc interactive. An extension of the CD format designed around a set-top
computer that connects to a TV to provide interactive home entertainment, including digital
audio and video, video games, and software applications. Defined by the Green Book
standard. CD-i Assn.

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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.
Dolby Surround The standard for matrix encoding surround-sound channels in a stereo

signal by applying a set of defined mathematical functions when combining center
and surround channels with left and right channels. The center and surround channels
can then be extracted by a decoder such as a Dolby Pro Logic circuit which applies
the inverse of the mathematical functions. A Dolby Surround decoder extracts
surround channels, while a Dolby Pro Logic decoder uses tially independent of the
recording or transmission format. Both Dolby Digital and MPEG audio compression

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systems are compatible with Dolby Surround audio.

DTS Digital Theater Sound. A perceptual audio-coding system developed for theaters. A

competitor to Dolby Digital and an optional audio track format for DVD-Video.
DVCD Stands for Double Video CD -- pretty popular format in mainland China.
Format itself is nothing new really, its just a regular VideoCD overburned to include 90 to
99mins per CD, compared to regular 74mins per CD in standard VideoCD format.
DVD An acronym that officially stands for nothing, but is often expanded as Digital Video

Disc or Digital Versatile Disc. The audio/video/data storage system based on 12-and

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8-cm optical discs.

DVD+R DVD+Recordable defines a standard for recordable DVD drives and media defined
by the DVDRW Alliance. Often called "plus R", the format is write once (compared to
DVD+RW wich can be erased and rewritten). The single sided discs can hold 4,700,000,000
bytes (4.38 Gigabytes at 1024 bytes to the kilobyte) with double sided discs holding twice as
much. There are no dual layer single sided recordable discs. This format competes with the
DVD Forum DVD-R specification. DVDRhelp DVDR information

JPEG Joint Photographic Experts Group. The international committee which created its

namesake standard for compressing still images.
Karaoke Literally empty orchestra. The social sensation from Japan where sufficiently

inebriated people embarrass themselves in public by singing along to a music track.

Karaoke was largely responsible for the success of laserdisc in Japan, thus supporting

it elsewhere.

Kodak Picture CD Kodak Picture CD is a CD that contains your pictures in JPEG
format(.jpg) along with software that lets you view, enhance, share, and print your pictures
from your computer. Some standalone DVD Players supports this format also, but then only
for viewing. This format will also work on DVD Players that supports "JPEG file viewing"
but you may lose some Kodak Picture CD specific features. Kodak Picture CD.

Macrovision An antitaping process that modifies a signal so that it appears unchanged on

most televisions but is distorted and unwatchable when played back from a videotape

recording. Macrovision takes advantage of characteristics of AGC circuits and burst

decoder circuits in VCRs to interfere with the recording process.

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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. Although this is
a LOSSY process, it can yield very high quality audio files are relatively high compression
rates.
A typical MP3 file encoded at 128 kbit/s (12:1 compression) is near CD quality.
MP3 audio is increasingly being used in video production coupled with various MPEG-4
video codecs like divx. The audio may be encoded with a constant or variable bitrate.
Multiangle A DVD-Video program containing multiple angles allowing different views of a

scene to selected during playback.
Multilanguage A DVD-Video program containing sound tracks and subtitle tracks for more

than one language.
RGB Video information in the form of red, green, and blue tristimulus values. The

combination of three values representing the intensity of each of the three colors can

represent the entire range of visible light.
S/N Signal-to-noise ratio. Also called SNR.

SACD Super Audio CD is the next generation of audio disc, offering full-range,
uncompressed digital multi-channel surround sound. SACD can also be backward compatible
using so called hybrid discs with an extra layer that allows them to be played on conventional
CD players but then only with ordinary CD quality. SACD can be played on SACD Players,
DVD Players with SACD support and if using hybrid discs also CD Players. SACD is
currently competing with DVD-Audio as the new audio defacto standard. Philips SACD
information.

Subtitle A textual representation of the spoken audio in a video program. Subtitles are often

used with foreign languages and do not serve the same purpose as captions for the

hearing impaired.

SVCD SVCD stands for 'Super VideoCD'. A SVCD is very similiar to a VCD, it has the
capacity to hold about 35-60 minutes on 74/80 min CDs of very good quality full-motion
MPEG-2 video along with up to 2 stereo audio tracks and also 4 selectable subtitles. A SVCD
can be played on many standalone DVD Players and of course on all computers with a
DVD-ROM or CD-ROM drive with the help of a software based decoder / player.
SVCDHelp.com.

S-video A video interface standard that carries separate luma and chroma signals, usually on

a four-pin mini-DIN connector. Also called Y/C. The quality of s-video is

significantly better than composite video since it does not require a comb filter to

separate the signals, but it’s not quite as good as component video. Most high-end

televisions have s-video inputs. S-video is often erroneously called S-VHS.
System menu The main menu of a DVD-Video disc, from which titles are selected. Also

called the title selection menu or disc menu.

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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. If you're familiar with regular audio/music CDs, then you will know what
a VCD looks like. A VCD has the capacity to hold up to 74/80 minutes on 650MB/700MB
CDs respectively of full-motion video along with quality stereo sound. VCDs use an encoding
standard called MPEG-1 to store the video and audio. A VCD can be played on almost all
standalone DVD Players and of course on all computers with a DVD-ROM or CD-ROM
drive with the help of a software based decoder / player. VCDHelp.com.

YUV In the general sense, any form of color-difference video signal containing one luma

and two chroma components. Technically, YUV is applicable only to the process of

encoding component video into composite video.

WMF Windows Media Format files are audio/video files encoded with the Windows Media
Encoder, providing high quality and media security for streaming and download-and-play
applications on PCs, set-top boxes, and portable devices. Windows Media Format comprises
Windows Media Audio and Video codecs, an optional integrated digital rights management
(DRM) system, and a file container. Microsoft WMF Information
CVD China Video Disk - a precursor to SVCD marketed since 1998. Resolutions are
352x480 NTSC, 352x576 PAL, 44.1khz audio (unlike 1/2 D1 DVD that is the same
resolution at 48khz audio). Not all players will play CVD (compatible players). CVD Guide
DivX DivX™ is a new format for digital video, much like MP3 is a format for digital music.
DivX™ is the brand name of a patent-pending video compression technology created by
DivXNetworks, Inc., (also known as Project Mayo). The DivX™ codec is based on the
MPEG-4 compression standard. This codec is so advanced that it can reduce an MPEG-2
video (the same format used for DVD or Pay-Per-View) to ten percent of its original size.
DivX.com.
DVD+RW DVD+RW is a ReWriteable media format of the DVD+R standard.

DVD-Audio DVD-Audio or sometimes called DVD-A is a separate format from DVD-Video.

It is a format specifically designed to provide the highest possible audio fidelity capable on

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DVD. DVD-Audio provides for audio in stereo and in multi-channel surround in a wide range
of specifications. In addition to audio, a DVD-Audio disk can contain a limited amount of
video, which can be used to display text, such as lyrics or notes. DVD-Audio can only be
played on DVD Players with DVD-Audio support (most DVD Players do not support this
format). DVD-Audio is currently competing with SACD as the new audio defacto standard.
DigitalAudioGuide DVD Audio FAQ

DVD-R DVD-Recordable defines a standard for recordable DVD drives and media defined
by the DVD Forum. Often called "minus R", the format is write once (compared to DVD-RW
wich can be erased and rewritten). The single sided discs can hold 4,700,000,000 bytes (4.38
Gigabytes at 1024 bytes to the kilobyte) with double sided discs holding twice as much. There
are no dual layer single sided recordable discs. This format competes with the DVD+R format.
DVDRhelp DVDR information

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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.

DVD-Video DVD-Video is the video element of the DVD format. DVD Demystified

DVD-Video Features.
DVD±R A term used to cover both the DVD-R and DVD+R standards in one word.

HDCD High Definition Compatible Digital® (HDCD®) is a patented encode/decode

process for delivering the full richness and detail of the original microphone feed on Compact
Discs and DVD-Audio. HDCD has been used in the recording of more than 5,000 CD titles,
which include more than 250 Billboard Top 200 recordings and more than 175 GRAMMY®
nominations, and account for more than 300 million CDs sold.

HDCD-encoded CDs sound better because they are encoded with 20 bits of real musical
information, as compared with 16 bits for all other CDs. HDCD overcomes the limitation of
the 16-bit CD format by using a sophisticated system to encode the additional 4 bits onto the
CD while remaining completely compatible with the existing CD format. HDCD provides
more dynamic range, a more focused 3-D soundstage, and extremely natural vocal and
musical timbre. With HDCD, you get the body, depth, and emotion of the original
performance not a flat, digital imitation.

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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 pre­cautions when a set is being serviced .

·Precautions during Servicing

1. Locations requiring special caution are denoted by labels and inscriptions on the rear panel and certain

parts of the product. When performing service, be sure to read and comply with these and other
cautionary notices appearing in the operation and service manuals .

2. Parts identified by the symbol in schematic diagram parts are critical for safety.

Replace only with specified part numbers.
Note : Parts in this category also include those specified to comply with laser emission standards for

Products using cathode ray tubes and those specified for compliance with various regulations
regarding spurious radiation.

3. Use Specified internal wiring. Note especially:

1) Double insulated wires

2)High voltage leads

4. Use specified insulating materials for hazardous live parts. Note especially:

1)Insulation Tape

2)PVC tubing

3)Spacers

4)Insulation sheets for transistor

5. Observe that wires do not contact heat producing

PARTS (heatsinks, oxide metal film resistors ,fusible resistors ,etc .)

!

6.Check that replaced wires do not contact sharp edged or pointed parts .

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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 .

9. The internal wiring is secured so as not to approach the heating parts and high voltage parts by its shape.
So, these wires must be restored to its former state.

10. After updated the hazardous live part or accessible part, if the clearance or creepage distance cann’t
accord with the safe request, then need adopt reinforced insulation method for ensure safety.

SAFETY CHECK AFTER SERVICING

Examine the area surrounding the repaired location for damage or deterioration. Observe that screws ,parts

and wires have been reterned to original positions .
Afterwards ,perform the following tests and confirm the specified values in order to verify compliance wit
atfety standards .

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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
jacks ,earphone jacks ,etc.)See table below .

·Clearance distance
When replacing primary circuit components ,confirm specified clearance distance (d),between soldered
terminals ,and between terminals and surrounding metallic parts .See table below.

Table 1: Ratings for selected areas

Insulation

AC Line Voltage Region

*110 to 240 v

110 to 230 v
*Class ll model only .
Note . This table is unofficial and for reference only . Be sure to confirm the precise values for your
particular country and locality.

USA,Australia

Europe

Resistance

F

4M/500VDC

Dielectric

Steength

4kv/minute F 6mm(d)

Clearance

Distance(d),(d)

· Leakage Current test
Confirm specified or lower leakage current between B(earth ground ,power cord plug prongs ) and
externally exposed accessible (RF terminals ,antenna terminals ,video and audio input and output
terminals ,microphone jacks ,earphone jacks ,etc .)

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m

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 .

AC Line Voltage

2k ohm

100 to 130 v
200 to 240 v

50k oh

Note . This table is for IEC member only . Be sure to confirm the precise values for your particular country

and locality.

Region Load Z Leakage Current(i)

<or= 0.7mA peak

Europe

Australia

<or= 2mA DC

<or=0.7mA peak

<or= 2mA DC

Earth Ground

(B) to :

Antenna earth

Terminals

Other terminals

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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. You can rename

it on PC before recording.

c) The upgrading software MTK.BIN must be in root directory. Recording mode must be ISO9660

(MODE1, LEVEL1), DO NOT SELECT JOLIET, LOOSEN ISOSTRICT.

2. Load the disc

3. DVD will read disc, and prompt upgrading. Press “PLAY” on remote to confirm upgrading.

Note: Do not turn off the player while under upgrading; do not let electricity cut off. Otherwise the player
will halt and never be operate again.
If the DVD player cannot read the disc, please record some data file (trash files that the player cannot
support) before recording upgrading software.

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A

A

A

0

Electrical Performance Standards

No. Test item Requirement

1

2 Audio amplitude/frequency response (dB)

3

4

5

6 Cross-Sound base wave (dB) ≥80

7 1KHz Channel Balance (dB)

8 Intermodulation Distortion (dB)

9 Frequency error (dB) ±0.02

10

11

12

13

14 Output Intensity (iput 1KHz 20mVp-p)

15 Distortion and Noise (%)

16 Frequency Response (dB)

nalog output level(V) (Virtual value) 1.0~2.0v

20Hz ±1
125Hz ±1
1KHz ±1
10KHz ±1
18KHz ±1
20KHz ±1

udio SNR (dB) (A) ≥90

udio distortion and noise (dB) (1KHz) ≤-65

Dynamic Range (dB) (1KHz)

0

AUDIO FEATURE

Level non-linear (dB)

Digital out level (V) (Vp-p)

De-bass function (dB)

disc 784

DTS Test DOLBY Test

MIC

-10

-20

-40

-60

 12   12  -4.53±1

 13   13  -9.04±1

DTS

DOLBY

FL

FR

C

SL

SR

SW

120Hz ±3

5KHz ±3

dB 1KHz

output Level

Reference Level

≥80

≤1

≤-50

±1

0.5±0.05

Amplitude Response
under 0dB output

level (dB)

(20Hz-20KHz)

Reference Level

Amplitude Response

+0.5/-1.0(dB)

(20Hz-20KHz)

2.5±0.5V

≤0.5

17

18

19

20

Frequency error (dB)

Short Read Time (Sec)

other

Long Read Time (Sec)

Max Power Consumption (W)

≥45

≤5

≤10

15

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Electrical Performance Standards

No.

21

22

23

24

25
26
27
28

29

30
31

32

33

34

35

36

37

38

39

40

VIDEO FEATURE

Test item Requirement

Video Output Level

Vp-p(V)

Horizontal Definition (TV)

S video output

CVBS

FEAT

URE

Y, U , V
FEAT

URE

Luminance channel bandwidth

and Amplitude Response

(MHz)

Chroma channel bandwidth

and amplitude response (MHz)

Luminance non-linear distortion (%) ≤5

Luminance Wave distortion (%) ≤10
Luminance SNR (dB) ≥50
Chroma SNR (dB) AM≥60 PM≥50
Luminance/Chroma signal delay (ns) ≤100
Differential plus DG (%) ≤5
Differential Phase DP (°) ≤5

S-video signal amplitude Vp-p

load (mV)

S-video signal bandwidth and

amplitude response (MHz)

S-video signal SNR (Db)

YUV output signal amplitude

Vp-p load(mV)

YUV output signal bandwidth

and amplitude response (MHz)

YUV output signal SNR

(Db)

RGB output signal amplitude

Vp-p load(mV)

RGB output signal bandwidth
and amplitude response (MHz)

RGBoutput signal SNR

(Db)

CVBS output

Line Sync amplitude

VCD

AV output

VCD

SVCD

DVD

VCD

SVCD

DVD

Y channel 700±140

C channel

Y channel

C channel

Y channel

C channel

Y channel

U channel

V channel

Y channel

U channel

V channel

Y channel

U channel

V channel

R channel

G channel

B channel

R channel

G channel

B channel

R channel

G channel

B channel

Y channel

SVCD

DVD

VCD

SVCD

DVD

Chorma
Chroma

Sync

≥3.5-20dB

≥3.5-20dB

≥3.5-23dB
≥3.5-24dB

≥50

≥50

1.0±0.2

0.3±0.05

≥250

≥350

≥450

≥250

≥350

≥500

≥5.5-6dB

≥1.5-6dB

880±176

300±60

≥5.5-6dB

≥1.5-6dB

≥50

≥50

700±140

700±140

700±140

≥5.5-6dB

≥2-6dB

≥2-6dB

≥50

700±140

700±140

700±140

≥5.5-6dB

≥5.5-6dB

≥5.5-6dB

≥50

≥50

≥50

4-2

Package (Inbox)and Block Diagrams

1

2

6

7

3

4

5

8

9

10

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

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DVD Box Block Diagram

6-1