Philips MCB-275 Service Manual

Micro System

MCB275/05

TABLE OF CONTENTS

Page

Location of PC Boards & Versions Variation ........................1-2

Speciﬁ cations .......................................................................1-3

Measurement Setup .............................................................1-4

Service Aids, Safety Instruction, etc .....................................1-5

CD Playability Check ..................................................1-6 to 1-8

Disassembly Instructions & Service positions .........................2

Service Test Program ...........................................................3-1

Set Block Diagram ................................................................4-1

Set Wiring Diagram ..............................................................5-1

Main Board ..............................................................................6

Key & LCD Board ....................................................................7

CD & MCU Board ....................................................................8

Mechanical Exploded View & Parts List ..................................9

Revision list ...........................................................................10

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.

Published by SL0913 Service Audio Printed in The Netherlands Subject to modiﬁ cati

Version 1.4

CLASS 1

LASER PRODUCT

3141 785 31774

VERSION VARIATIONS

VERSION VARIATIONS:

Type /Versions: MCB275

Features & Board in used:

Line Out Video Out Surround Out Subwoofer Out Power Booster Out Digital Out Digital in Matrix Surround

Dolby Pro Logic (DPL) Incredible Surround Karaoke Features Voltage Selector ECO Power Standby (LCD Display Off) x ECO6 Tuner Board - Systems Non-Cenelec ECO6 Tuner Board - Systems Cenelec USB Direct

1-2

/05

xni RDC / ni xuA

xSDR

xsweN

x x

SPECIFICATIONS

GENERAL:

Mains voltage : 127/240V -15%+10% Switchable for /98

120V ± 10% for /37

230V ± 10% for /05/12

Mains frequency : 50/60Hz

Clock accuracy : < 4 seconds per day

Dimension centre unit :194(W)x269(H)x90(D) (mm)

1-3

Dynamic Bass Boost (DBB) : ON / OFF Input sensitivity

Aux in (at 1kHz) : 500mV at 600 Ω

USB : Host

Output sensitivity

Headphone output at 32 Ω : 10mW ± 2dB (Max. vol.)

Power consumption

Active : 20W

Standby : < 5.5W (DEMO mode)

ECO Power Standby : < 0.5W for /05/12/37

TUNER:

Tuning range : 87.5-108MHz

Grid : 50kHz for /98/12/05

100kHz for /98/55/37

IF frequency : 10.7MHz ± 20kHz

Aerial input : 75 Ω coaxial /05/12/98

300 Ω for /37

Sensitivity at 26dB S/N : < 22µf

Selectivity at 300kHz bandwidth : > 25dB

Image rejection : > 25dB [> 75dB]

IF rejection : > 60B [> 80dB]

Distortion at RF=1mV, dev. 75kHz : < 3%

-3dB Limiting point : < 23.5dBf

Crosstalk at RF=1mV, dev. 40kHz : > 18dB

COMPACT DISC:

Frequency response within ± 3dB : 125Hz - 16kHz

Output level (in Vrms) : 500mV, Z

= 100Ω

out

Signal/Noise ratio (unw.) : > 65dB

Signal/Noise ratio (A-weighted) : > 76dB

Distortion at 1kHz : < 0.02%

Channel unbalance (-40dB) : < ±2dB

Channel separation at 1kHz : > 30dB

Emphasis : 15/50 µS (switched

automatically by CD10)

THD Noise(1kHz,500mW) : < 1.0%

Volume attenuation(1kHz) : > 60dB

MP3 CD WMA:

MP3 : MPEG 1 (ISO/IEC 11172-3)

Layer3

MP3-CD Bit Rate : 8-320 kbps WMA-CD Bit Rate

: 64-192 kbps

Sampling Rate : 8, 11.025, 12, 16, 22.05, 24, 32, 44.1, 48 kHz Format

: ISO9660, Joliet,UDF

ID3 : V1 tag/V2 2.0/V2 3.0

Language Support : English

Tuning range : 531-1602kHz for /05/12/55/98

530-1700kHz for /37/98

Grid : 9kHz for /05/12/55/98

10kHz for /37/98

IF frequency : 450kHz ± 1kHz

Aerial input : Frame aerial 18.1µH

Sensitivity at 26dB S/N : < 4.4mV/M

Selectivity at 300kHz bandwidth : > 18dB

IF rejection : > 45dB

Image rejection : > 28dB

Distortion at RF=50mV, M=80% : < 5%

AMPLIFIER:

Output power

L & R : 2 x 5.0W (4Ω, 1kHz, 10% THD)

:2 x 4.5W (4Ω, 1kHz, 10% THD) /98

:2 x 4.5W (FTC Power, 4Ω, 1kHz, 10% THD

63Hz-12.5kHz) /37

Frequency response within -3dB : 50Hz-16kHz

Digital Sound Control (DSC) : Jazz / Rock / Pop / Classic

[....] Values indicated are for /05/12 only.

MEASUREMENT SETUP

Tuner FM

1-4

Bandpass

LF Voltmeter

e.g. PM2534

RF Generator

e.g. PM5326

DUT

250Hz-15kHz

e.g. 7122 707 48001

Ri=50Ω

S/N and distortion meter

e.g. Sound Technology ST1700B

Use a bandpass filter to eliminate hum (50Hz, 100Hz) and disturbance from the pilottone (19kHz, 38kHz).

Tuner AM (MW,LW)

RF Generator

e.g. PM5326

Ri=50Ω

DUT

Frame aerial

e.g. 7122 707 89001

Bandpass

250Hz-15kHz

e.g. 7122 707 48001

LF Voltmeter

e.g. PM2534

S/N and distortion meter

e.g. Sound Technology ST1700B

To avoid atmospheric interference all AM-measurements have to be carried out in a Faraday´s cage. Use a bandpass filter (or at least a high pass filter with 250Hz) to eliminate hum (50Hz, 100Hz).

Use Audio Signal Disc (replaces test disc 3)

DUT

SBC429 4822 397 30184

S/N and distortion meter

e.g. Sound Technology ST1700B

LEVEL METER

e.g. Sennheiser UPM550

with FF-filter

Recorder

Use Universal Test Cassette CrO2 SBC419 4822 397 30069

or Universal Test Cassette

LF Generator

e.g. PM5110

Fe SBC420 4822 397 30071

DUT

S/N and distortion mete

e.g. Sound Technology ST1700B

LEVEL METER

e.g. Sennheiser UPM550

with FF-filter

SERVICE AIDS

1-5

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

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

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

CD PLAYABILITY CHECK

Customer complaint

"CD related problem"

check playability

1-6

Set remains closed!

playability

ok ?

Play a CD

for at least 10 minutes

check playability

playability

ok ?

"fast" lens cleaning

check playability

playability

ok ?

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

4 is recommended

Standard repair procedure

clean the lens

check playability

playability

ok ?

check "EYE-Pattern"

return set

add Info for customer

"SET OK"

return set

1 - 7

For description - see following pages

replace Signal Processor

return set

EYE-Pattern

ok ?

check Laser current

Laser current

ok ?

check CD Drive offsets

CD Drive offsets

ok ?

replace CD Drive

return set

replace CD Drive

return set

replace CD Drive

return set

CD PLAYABILITY CHECK

1-7

PLAYABILITY CHECK

For sets which are compatible with CD-RW discs

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 ≥10seconds

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

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.

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.

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

VCC

VREF

1800

+5V_HF

VrefCD10

B C F

GND

Laser power control

100n

2878

470n

2876

3821

3823

2880

33p

+5V

BC807-40

7879

3817

47R

3820

4R7

47R

3819

2879

2877

47u

7811-A

LM358D

10K

3822

47R

3818

2841

100n

47n

2869

+5V_HF

LASER DIODE

U >250mV

->Laser damaged !

4,6V

3,3V

3,9V

0,17V

Sanyo DA12T3

HF-Amplifier

680R

3905

3903 3K3

BC847B

7877

47n

2818

1K5

3902

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

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

1-8

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.

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 ≥350mV MCDxx : 170-230mV ≥300mV DA1x : 210-250mV ≥350mV DA2x : 175-200mV ≥250mV Use SBC444A (CD-DA) for measurement.

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

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 Service Test 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.

DISMANTLING INSTRUCTIONS

2-1 2-1

Dismantling the Rear Portion and PCBs

1) Press the 2 juts and pull out the Stand as shown in figure

Figure 1

Figure 2

Dismantling the Rear Portion and PCBs

5) Loosen 2 screws E to remove the Bracket Jack Board as

shown in Figure 4.

6) Loosen 3 screws F to remove the Main Board as shown

in figure 5.

Figure 4

2) Loosen 5 screws A and 6 screws B to remove the Rear

Cabinet as shown in figure 2.

3) Loosen 3 screws C to remove the SP & ANT Jack Board

as shown in figure 3.

4) Loosen 5 screws D to remove the Power Module as

shown in figure 3.

Figure 5

Dismantling of the Display Lens & the Volume knob

1) Use a flat head screw driver to give a push in the direction

as shown in figure 6.

2) Place two small screw drivers in between the front cabinet

& knob to give more leverage in pulling out the Volume

Knob as shown in figure 7.

Figure 3

Figure 7

Figure 6

Dismantling of the CD Module & CD Door Carrier

1) Loosen 5 screws J mounting the Key Board to the Front

Cabinet to remove the Key Board as shown in figure 8.

2) Loosen 4 screws H and 3 screws G to CD Module as

shown in figure 8.

3) Loosen 2 screws I to remove the Servo Motor Mechanism

as shown in figure 8.

2-2

Service pos A

Figure 8

4) Loosen 4 screws K to remove the Right CD Door Carrier

and 4 screws L to remove the Left CD Door Carrier as

shown in figure 9.

Service pos B

Figure 9

Note: After re-assembly, it is very important to ensure all

wires are routed properly to ensure that they do not

touch/obstruct all moving parts.

SERVICE TEST PROGRAM

3-1

KEY TEST

Button pressed?

Display shows

Table 1

To enter Service

Testprogram hold DBB & Source buttons depressed for 3 sec.

at USB mode (no USB).

Display shows the

MCU version

“ V. yy ”

(Main menu)

Figure 1

Door switch is ignored →

V refers to Version yy refers to Software version number of the uProcessor

(counting up from 01 to 99)

CD door can be opened.

DISPLAY TEST

Button pressed?

Display shows Figure 1 All display flags on.

Button pressed?

Display shows alternate

segment display from SEG0

to SEG64.

ADC TEST

DBB

Button pressed?

Display shows "ADC0 Value"

for ADC0

(Input Line - For key scanning)

DBB

Button pressed?

Display shows "ADC1 Value"

for ADC1

(Input Line - ioNTC Heat detection for transformer)

TEST

LEAVE SERVICE TEST PROGRAM

other Tests

RAELC MORP

Various

Activated with

PROGRAM

to Exit

Disconnect mains cord

ACTION

set

"EEP CLR" is displayed while the erase processing.

Caution! All presets from the customer will be lost!!

.MORPEE eht ot tnes eb lliw nrettap t

KeyNr Set key KeyNr Set key KeyNr Set key

0 CD 10 RDS 20 PROGRAM

1 AUX 11

2 TUNER 12 CLOCK/DISP

3 SOURCE 13 ALBUM + SLEEP

STANDBY/ON

OPEN/CLOSE

VOLUME DOWN

7 VOLUME UP 17 NULL 27 MUTE

8 NULL 18 NULL 28 USB

9 NULL 19 REPEAT

Key test table

21 SHUFFLE

LAY

14 ALBUM - TIMER

SKIP PREV 25 DBB

16 SKIP NEXT 26 DSC

Table 1

22 NULL

23 24

Button pressed?

No Display shows

Button pressed?

ADC Test is used for checking the ADC inputs to the microprocessor.

The display shows an ADC value between 0 and 255 for an input signal between 0 and 5V.

DBB

Button pressed?

Display shows "ADC2 Value"

for ADC2

(Input Line - Rotary volume)

DBB

Button pressed?

Display shows "ADC3 Value"

for ADC3

(Input Line - Door switch status)

DBB

Button pressed?

Display shows "ADC4 Value"

for ADC4

(Input Line - Version detection)

Button pressed?

+ 23 hidden pages