Philips MCD-755 Service Manual

DVD Micro theatre

�

MCD755

all versions

TABLE OF CONTENTS

Service Aids ..................................................................................1-1

Info. about lead-free soldering.......................................................1-1

Service Instruction ........................................................................1-1

CD Playability Check .............................................................2-1..2-3

Disassembly digram ...............................................................3-1..3-5

Software version check and upgrading .........................................4-1

Block diagram ................................................................................5-1

Wiring diagram .............................................................................6-1

Tuner Board

circuit diagram ..........................................................................7-1

layout diagram ..........................................................................7-2

VFD Board

circuit diagram ..........................................................................8-1

layout diagram ..........................................................................8-2

©

All rights reserved. No part of this publication may be reproduced, stored in a retrieval system or transmitted, in any form or by any means, electronic, mechanical, photocopying, or otherwise without the prior permission of Philips.

CPU Board

circuit diagram. .........................................................................9-1

layout diagram ..................................................................9-2...9-3

AMP Board

circuit diagram ........................................................................10-1

layout diagram ..............................................................10-2..10-3

Exploded view diagram ...............................................................11-1

Service partslist ..................................................................12-1..12-2

Commercial partslist

Published by LX 0737 Service Audio Subject to modification

Version 1.0

3141 785 32120

SERVICE AIDS

1-1

Service Tools:

Universal Torx driver holder .................................4822 395 91019

Torx bit T10 150mm ...........................................4822 395 50456

Torx driver set T6-T20 .........................................4822 395 50145

Torx driver T10 extended .....................................4822 395 50423

GB

All ICs and many other semi-conductors are susceptible to electrostatic discharges (ESD). Careless handling during repair can reduce life drastically. When repairing, make sure that you are connected with the same potential as the mass of the set via a wrist wrap with resistance. Keep components and tools also at this potential.

WARNING

GB

Safety regulations require that the set be restored to its original condition and that parts which are identical with those specified, be used

Safety components are marked by the symbol

!

.

Compact Disc:

SBC426/426A Test disc 5 + 5A ...........................4822 397 30096

SBC442 Audio Burn-in test disc 1kHz .................4822 397 30155

SBC429 Audio Signals disc .................................4822 397 30184

Dolby Pro-logic Test Disc ....................................4822 395 10216

ESD

CLASS 1

LASER PRODUCT

Lead free

2 -1

CD PLAYABILITY

Customer complaint

"CD related problem"

check playability

for at least 10 minutes

CHECK

playability

ok ?

Y

Play a CD

Set remains closed!

1

N

"fast" lens cleaning

check playability

playability

ok ?

Y

3

For flap loaders (= access to CD drive possible) cleaning method

is recommended

4

Standard repair procedure

N

clean the lens

check playability

4

check playability

playability

ok ?

Y

add Info for customer

"SET OK"

return set

1

- 7

For description - see following pages

2

5

6

7

Y

return set

N

replace CD Drive

return set

N

replace CD Drive

return set

playability

ok ?

N

check "EYE-Pattern"

EYE-Pattern

ok ?

Y

check Laser current

Laser current

ok ?

Y

check CD Drive offsets

replace Signal Processor

return set

Y

CD Drive offsets

N

ok ?

replace CD Drive

return set

2-2

CD PLAYABILITY

CHECK

1

PLAYABILITY CHECK

For sets which are compatible with

use CD-RW Printed Audio Disc....................7104 099 96611

TR 3 (Fingerprint) TR 8 (600µ Black dot) maximum at 01:00

• playback of these two tracks without audible disturbance playing time for: Fingerprint ≥

Black dot from 00:50 to 01:10

• jump forward/backward (search) within a reasonable time

For all other sets

use CD-DA SBC 444A..................................4822 397 30245

TR 14 (600µ Black dot) maximum at 01:15 TR 19 (Fingerprint) TR 10 (1000µ wedge)

• playback of all these tracks without audible disturbance playing time for: 1000µ wedge ≥10seconds

Fingerprint ≥10seconds Black dot from 01:05 to 01:25

• jump forward/backward (search) within a reasonable time

CD-RW discs

10seconds

4

LIQUID LENS CLEANING

Before touching the lens it is advised to clean the surface of the lens by blowing clean air over it. This to avoid that little particles make scratches on the lens.

Because the material of the lens is synthetic and coated with a special anti-reflectivity layer, cleaning must be done with a non-aggressive cleaning fluid. It is advised to use “Cleaning Solvent B4-No2”, available with codenumber 4822 389 10026.

The actuator is a very precise mechanical component and may not be damaged in order to guarantee its full function. Clean the lens gently (don’t press too hard) with a soft and clean cotton bud moistened with the special lens cleaner.

The direction of cleaning must be in the way as indicated in the picture below.

2

CUSTOMER INFORMATION

It is proposed to add an addendum sheet to the set which informs the customer that the set has been checked carefully - but no fault was found. The problem was obviously caused by a scratched, dirty or copy-protected CD. In case problems remain, the customer is requested to contact the workshop directly. The lens cleaning (method 3) should be mentioned in the addendum sheet.

The final wording in national language as well as the printing is under responsibility of the Regional Service Organizations.

3

FAST LENS CLEANING (dry brush)

Use lens cleaning CD

SBC AC300...........................................9082 100 00043

Insert the lens cleaning CD, press PLAY and follow the voice guide´s instructions on the CD.

Sanyo DA12T3

CD Drive

A

F

C

B

E

C

D

E

VCC

B

VREF

F

D

9

10

11

12

13

14

15

16

1800

+5V_HF

VrefCD10

A

D

E

B C

F

GND

8

E

D

A

B

C

F

Laser power control

100n

2878

470n

2876

3821

1R

1K

3823

2880

33p

+5V

BC807-40

7879

3817

47R

3820

4R7

47R

3819

1n

2879

2877

47u

1

8

4

7811-A

LM358D

3

2

10K

3822

47R

3818

2841

100n

47n

2869

+5V_HF

LASER DIODE

U >250mV

->Laser damaged !

4,6V

3V

3,3V

3,9V

2V

0,17V

Sanyo DA12T3

HF-Amplifier

D3

D2

D1

680R

3905

3903 3K3

BC847B

7877

47n

2818

1K5

3902

5

7

4

2

1

6

3

64

8

9

10

11

470R

3893

+3.3V

2K2

3908

10K

3923

BC847B

7878

BC847B

7876

4n7

2813

3896 100R

220u

2885

2881 560p

47n

2887

560R

3901

2883 470n

2817

4u7

3n3

2814

3898 220R

3895

27K

470n

2884

+3.3V

3909

820R

3907

100R

3920

33K

3897

2882

82p

3K3

3904

2K7

3899

3906

470R

+5V_HF

HFIN

VrefCD10

100p

28152816

22n

LDON to 3826,3827

VREF GE

VDDA1

VRIN

VSSA1

ISLICE

LD

ON

D1

D2

D3

D4

HFIN

HFREF

IREF

CD_DA: 0V / CD_RW: 3V

Σ

(A-D)

800mVpp

TB = 0.5µs/div

EYE-PATTERN

1,8V

1,2V

2,4V

2,6V

0,65V

CD PLAYABILITY CHECK

2-3

5

EYE-PATTERN SIGNAL – JITTER MEASUREMENT

Measure the signal on the input of the Signal processor using an analog oscilloscope. Please find the exact measuring point in your Service Manual.

See below examples of the signal. Amplitude should read at least 700mVpp using SBC444A.

6

CD DRIVE – LASER CURRENT MEASUREMENT

The laser current can be measured as a voltage drop on a resistor. The resistor is marked in every Service Manual. The value depends on the type of CD drive.

typical value most probably defect

VAMxxxx : 150-230mV MCDxx : 170-230mV DA1x : 210-250mV ≥350mV DA2x : 175-200mV Use SBC444A (CD-DA) for measurement.

≥

350mV

≥

300mV 250mV

≥

If the oscilloscope shows a signal like the ‘bad’ one, and/or the amplitude decreases within 1 minute - the CD drive has to be replaced.

good

bad

7

CD DRIVE – OFFSET MEASUREMENT

The photodiodes of the CD-drive may have an offset. These offsets have to be compensated by the signal processor. High offsets can lead to poor playability of some CDs (skipping tracks).

To measure the offset values, start the Program - section “Focus Test” without a CD.

The offsets can be measured with a DC Millivoltmeter directly on the connector (see drawing below). Pin numbering varies from drive to drive.

The values from diode A-D should read 0±10mV. Diodes E and F are less critical.

If one of the offsets is higher than ±10mV the CD drive has to be replaced. Otherwise replace the Signal Processor.

Service Test

MCD755 Disassembly-DVD layer

Disassembly diagram

Page:62

A. Remove bottom cover B.Remove top cover and loosen screws 3×10PTH(4PCS), 3×8FT(2PCS)

A1.Loosen screws 2.5×7PWMTT(3PCS),2.6×5PWMTT(7PCS) B1. Loosen screws 3×10FA（1PCS）

A

C. Remove side plate and loosen screws 3×6BTH(4PCS),3×6FMTT(2PCS) C1. Loosen screws where is the back of side plank 3×4FMTT(4PCS)

Remove bezal panel and loosen screws 3×5FMTT(2PCS)

C

B1

B

C1

D.Loosen screws 3×10PWA(2PCS),3×8PWMTT(2PCS)and then remove mechanism core E.Loosen screws 3×10FA(7PCS),3×6FMTT(1PC),and

Disassembly diagram

Page:63

remove rear plate

E

D

F. Remove motor and loosen screws where is the front of side plate 3×6FT(2PCS), 3×10BT（2PCS） G.Loosen screws 3×6PM(6PCS), remove CPU

card and decode card

F

G

H. Loosen screws 2×6PWT(2PCS), remove slide plate

Disassembly diagram

Page:64

J.Loosen screws J1 2.6×8PT(7PCS) J2 2.6×5PT(4PCS) J3 2.6×6PT(2PCS), and remove top cover

H

J3

I. Loosen screws2.6×8PT(8PCS), and remove VFD board

J2

I

J1

MCD755 Disassembly-AMP layer

Disassembly diagram

Page:65

A.Looen screws2.6×5PWMTT(8PCS), remove plastic bottom cover B. Loosen screws 3×10PTH(6PCS) 3×6BTH(4PCS), remove side plank and top cover C. Loosen screws3×6FMTT(5PCS), remove bezal plank

A

D.Loosen screws 3×12FA(4PCS), 3×10FT(1PC), 3×5FMTT(4PCS), remove rear plank

D

B

C

E. Loosen screws 3×5BM(3PCS), remove connection card F. Loosen screws 3×5BM(4PCS), remove AMP board

Disassembly diagram

Page:66

E

G

F

G. Loosen screws 3×5BM(4PCS), remove power board

H. Loosen screws 2.6×8PT(6PCS), 2.6×5PT(2PCS), remove bezal panel

Disassembly diagram

Page:67

H

I. Loosen screws and remove top cover

I3

I1. 2.6×8PT (7PCS) I2. 2.6× 5PT（ 4PCS） I3. 2.6×6PT （2PCS）

I2

I1

4 - 1 4 - 1

SOFTWARE VERSION CHECK AND UPGRADING

TDA8922

TDA8920

TDA8922

PT2322

9228

24C02

PT2323

TUNER

BLOCK

IC:TEA5760

AUX2

AUX2 IN

AUX1

AUX1 IN

RED

R OUT

VIDEO

V-OUT

S-VIDEO

S-V OUT

COAXIAL

OPTICAL

GREEN

GR OUT

BLUE

B OUT

MEPG2

BLOCK

MECHANISM

DVD

STBY&MUTE

CONTROL

VFD

PT16311

REM1GND2Vcc

3

REM-SENSOR

CPU5V

+Vs

-Vs

DVD 12V

AC

SWITCH POWER

STANDBY

+12V

+Vs

-Vs

CPU5V

DVD 12V

DVD ON/OFF

TUNER POWER

TUNER IN

AUX2 IN

AUX1 IN

DVD MR

DVD ML

D-FL

D-FRSLSR

CEN

SW

CEN

SL

SR

FL

FR

FL

FR

SW

CEN

SL

SR

CPU

SDA

SCL

FR

FL

SL

SR

CEN

SW

KEY

CONTROL

FR

SR

CEN

SW

SL

FL

STANDBY

MUTE

SUR-MUTE

MUTE

SUR-MUTE

GND

SET BLOCK DIAGRAM

5 - 1