Philips MZ-9 Service Manual

Name: Philips MZ-9
Brand: Philips
SKU: 8187482
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Service

MZ-9/22

A02 - 174

Service

Product Service Group CE Audio

Service Information

Already published Service Informations :

CHANGES DURING PRODUCTION

FRONT BOARD

*From production week 0217 onwards the following has been changed

to solve Thin/Thick Disc readability problem and to improve on the Tape transition timings.

Change 7400 3139 110 53251 TMP87CS71F - 'MZ9S53251'

*From production week 0225 onwards the following has been changed

due to material end of life.

Change 7402 9322 140 83682 IC M24C01-BN6

ETF7 ND/DD/FR TAPE MODULE

*From production week 0218 onwards the ETF7 ND/DD/FR Tape

Module is introduced to replace the ETF5-FE ND/DD/FR Tape Module for cost savings. For this reason new layout and circuit drawing are enclosed (Page 9-1 to 9-14).

10 - 09 - 2002

3139 785 30089

9-1

ETF7 TAPE MODULE

Tapedeck wiring (Double deck)

TO ETF BOARD CONNECTOR 1770 (ND) 14P

CONNECTOR 1740 (DB) 14P

REC REV

CRO2*

REC FWD

9-1

CRO2*

* Not for Ferro version

(Non-Dolby Version)

TABLE OF CONTENTS

Tape Module Wiring & variation table ....................... 9-1

Block diagram ............................................................ 9-2

Brief Introduction ....................................................... 9-3

Connector assignment............................................... 9-4

Tape deck electronics & Tape adjustments ............... 9-5

ETF7 Non-Dolby board layouts ................................. 9-6

Analog Circuit diagram .............................................. 9-7

Servo Circuit diagram ................................................ 9-8

Exploded views & parts list........................................ 9-9

Electrical parts list.................................................... 9-13

MODE SW

Mechanism B Mechanism A

TO ETF BOARD CONNECTOR 1710 (ND) 5P

CONNECTOR 1720 (DB) 6P

–

TAPE DECK MOTOR

TO ETF BOARD CONNECTOR 1730 (3P)

Variations table for Analog Circuit

Autoreverse Non-autoreverse

ND/DD/FR ND/DD/FF

Chrome/Ferro Chrome/Ferro Ferro 2624 - - 100nF 2701 , 2702 150pF 270pF 270pF 2703 , 2704 100pF 220pF 220pF 2717 , 2718 10nF 15nF 15nF 2721 , 2722 6,8nF 6,8nF 2727 , 2728 470pF 1nF 1nF 3616 10k 1k 1k 3618 6k8 - 3620 10k trimmer - 3622 - 10k trimmer 10k trimmer 3672 4k7 - 3676 47k - 3687 220R 220R 3688 680R - 3723 , 3724 15k 18k 18k 3725 , 3726 10R 10R 3727 , 3728 5k6 6k8 6k8 3729 , 3730 3k3 4k7 4k7 3743 , 3744 1k5 2k2 2k2 3745 , 3746 3k3 5k6 5k6 3754 , 3755 1M 47R 47R

3769 12k 8k2 8k2 3772 6k8 5k6 5k6 4785 - - 0R jumper 3774 15k 8k2 8k2 6614 1N4148 - 7616 BC857B - 7622 BC847B - -

Autoreverse Non-autoreverse

ND/DD/FR ND/DD/FF

Chrome/Ferro Chrome/Ferro Ferro

BLOCK DIAGRAM

9-2

Line-In

Playback Head

Rec/Pb Head

Erase Head

ATTEN

BIAS SYM

HD SW.

REC

Rec current

BIAS ADJ

Bias

7710

SOURCE SEL HEF4952BT

1A0 1A1 1A2

7720

PRE-AMPLIFIER AN7318S

ALCEN

PLAYBACK EQUALISATION

ALC

7740

PB EON. SW. HEF4952BT

2A0 2A1 2A2

IEC I IEC II REC EON.

7730

REC EON. SW. HEF4952BT

3A0 3A1 3A2 (HS) (REC) (CRB)

4794 #

NOM/HI SPEED REC EON.

9792 #

For Dolby version only

PB A ADJ

1A0

MPX

Rec In

PB B ADJ

1A1

7640

RECORD AMP NJM4560D

NOM/HI SPEED REC EON.

PB In

7630

DOLBY B NR CXA1101M

DOLBY

REC ADJ

2A2

PB Out

ATTEN

PB Out

REC Out

MUTE

7788

2A2

NOTE:

Erase

# For Non-dolby version only Only 1 channel is presented.

MicroProcessor Control / Communication lines

Direct / Indirect Control lines from Shift Registers

OSCILLATOR

REC

CRB

1A0

REC

CRA

NS/HS (NS)

7622

7780

7787

7792

7791

ALCEN

1A2

1A1

2A0

3A0

3A0 NS

SOLENOID SUPPLY CTRL

MOTOR VCC SUPPLY CTRL

NS/HS CTRL

DECK(S) SW. STATUS TO VOLTS CONV.

SOLENOID SUPPLY CTRL

Deck B (Rec/Pb) switches, sensors & motor

AD1 AD2

CLK

DATA

STROBE

7610

SHIFT REGISTER HEF4094BT

1A0 2A1 2A2 REC NS/HS (NS)

Deck A (Pb) switches, sensors & motor

9-3 9-3

Brief introduction

General

Playback Mode Signal from the playback head Deck A or Deck B is selected and fed through by the Mode Selector IC7710 (HEF4952BT). The signal is amplified by amplifier IC7720 (AN7323S) before feeding to the IC7740 (HEF4952BT) and out to the AF Board via connector 1701.

Recording Mode

2. Recording Signal is selected and fed through by the Mode Selector IC7710 (HEF4952BT) which is then amplified by the amplifier IC7720 (AN7323S). The amplified output signal will pass through IC7730 (HEF4952BT) for record equalization and back to IC7710 (HEF4952BT) before registered into the Rec/PB Head of Deck B.

Dubbing Mode In Dubbing mode, signal from the playback head Deck A is selected and fed through by the Mode Selector IC7710 (HEF4952BT) which is then equalised for playback mode by the amplifier IC7720 (AN7323S) so that a flat response is obtained after the pre-amp. The equalised signal will then follow the same path as in the Recording mode.

Mode Selector

4. The Mode Selector IC7710 (HEF4952BT) caters for 4 inputs signal, namely Playback Signal from Deck A, Playback Signal from Deck B, Recording Signal and Dubbing Signal.

5. Amplifier PB/REC Amplifier IC7720 (AN7323S) is for the purpose of amplifying the Playback and Recording signal from the Mode Selector.

Automatic Level Control (ALC) ALC circuit consists of resistors (3760, 3765, 3766, 3767), capacitors (2762 , 2763) and control by transistor 7787 (BC847B). ALC limits the amplifier output to a constant value when input signal becomes too large, thus limiting recording current to below saturation level, to prevent recording distortion.

Muting Circuit (For Non-Dolby version only)

7. Switch S4 of the IC7740 (HEF4952BT) is for the purpose of muting the output during Recording mode. During Recording mode, S4 is closed and shorted to the ground.

8. IC7740 (HEF4952BT) The function of the IC7740 (HEF4952BT) is to change time constant between 120us Ferro (IEC I) and 70us Chrome (IEC II) during playback mode. It will automatically determined whether the tape type is 120us Ferro (IEC I) or 70us Chrome (IEC II). This IC will switch to Flat Gain during the Recording mode.

IC7730 (HEF4952BT) The function of the IC7730 (HEF4952BT) is to change gain and time constant according to tape type and recording speed to boost recording current at higher frequency during recording to compensate for head loss. It will automatically determined whether the tape type is 120us Ferro (IEC I ) or 70us Chrome (IEC II).

Bias Level

10. Bias Level making use of the Variable resistor (3773) for adjusting the optimal level of the bias current for Ferro or Chrome.

11.

Bias Symm (For Dolby B NR version only) Bias Symm making use of the Variable resistor (3785) to adjust the bias current for the left and the right channel to be equal.

PB Switch

12. Playback Switch which consists of the FETs 7785 (For Dolby B NR version only) & 7786 (J111) is for the purpose of providing a virtual ground for the Rec/PB Head (Deck B) during Playback mode. During the Playback mode, the FETs are turn on and shorted pin 2 and 4 of connector 1720 to the ground. During Recording mode, the FETs are turn off to allow the oscillator signal to be superposition onto the Recording signal for recording.

13.

Motor Speed (For FR versions only) During High speed dubbing, a feedback signal from the uP through pin 03 of the IC7610 (HEF4094BT) will trigger the transistors 7622 (BC847B) and 7616 (BC857B) to cause a change in the voltage level between High and Low, thus changing the speed of the motor.

IC7610 (HEF4094BT)

14. IC7610 (HEF4094BT) is a Shift Register use for issues the logic for cmos switch ICs (HEF4952BT) via 1A0, 2A1 and 2A2. It also issues logic to On/Off SOL_A, SOL_B and MOT. Recording speed is controlled via NS/HS.

Dolby Circuit (For sets with Dolby B NR version only)

15.

IC7630 (CXA1551M) IC7630 (CXA1551M) in the Dolby circuit is a Dolby Noise Reduction Type B IC for the Playback and Recording signal. Noise Reduction ON/OFF are controlled by DOLBY, which is from CLK, direct from uP. After clocking in DATA, CLK is set to HIGH/ LOW for NR OFF/ON.

19kHz Filter

16. The 19kHz filters 5631 & 5632 (LXD-210) in the Dolby circuit is for the purpose of filtering the 19kHz Pilot Tone (for Tuner signal only) of the Recording signal.

17. Level Adjust The Variable resistor 3635, 3636,3641 and 3642 in the Dolby circuit is for adjusting the playback level of the Dolby reference (400Hz , 200nWb/m). Transistor 7631, 7632 are ON to enable adjustment of 3641, 3642 during Playback Deck A. Transistor 7633, 7634 and 3635, 3636 are active for Playback Deck B.

18.

Amplifier IC7640 (NJM4560M) The Amplifiers 7640A & 7640B (NJM4560M) in the Dolby circuit is for the purpose of amplified the Recording signal.

Muting Circuit

19. The muting circuit which consists of transistors 7788, 7789 and 7790 (BC847B) is for the purpose of muting the output during Recording mode.

NOTATIONS & ABBREVIATIONS USED IN THIS DOCUMENT

CR Chrome (IEC type II) DB Dolby NR type B DD Double Deck DM Double Motor FE Ferro (IEC type I) FF Non-Autoreverse FR Autoreverse Deck B Gnd x Ground x HSD High speed dubbing ND Non Dolby NR Noise Reduction NSD Normal speed dubbing PB Playback REC Record S/A Sub-assy SD Single Deck SM Single Motor

CONNECTORS ASSIGNMENTS:

9-49-4

CONNECTOR 1701 INTERCONNECTION TO AF BOARD

1 REC-L Record input left 2 REC-R Record input right 3 GND A AF Ground 4 TAPE-L Playback output left 5 +12V D.C. supply (+12V) for AF electronics 6 TAPE-R Playback output right 7 -CMOS Negative d.c. supply (-9V) for CMOS ICs

CONNECTOR 1703 INTERCONNECTION TO AF BOARD

1 GND M Motor Ground 2 +MOTOR D.C. supply (+12V) for tape deck motor & solenoid

CONNECTOR 1706 INTERCONNECTION TO FRONT BOARD

1 AD2 Deck sensing switches output voltage / Deck A EOT 2 AD1 Deck sensing switches output voltage / Deck B EOT 3 +5V DC supply +5V for ADC network 4 GND P Control & Oscillator Ground 5 CLK HEF4094BT shift register Clock line 6 DATA HEF4094BT shift register Data line 7 STROBE HEF4094BT shift register Strobe line

CONNECTOR 1710 DECK B HEADS CONNECTON

1 B R/P HD L+ R/P Head left channel positive 2 GND A R/P Head return ground 3 B R/P HD R+ R/P Head right channel positive 4 ERASE HEAD Erase Head 5 GND A Erase Head ground

CONNECTOR 1720 DECK B HEADS CONNECTON

(For Non-Dolby version only)

(For Dolby B NR version only)

CONNECTOR 1740 DECK A & B CONTROL INTERFACE

1 REC REW Record tab protection status switch (reverse) [open=on: close=off] 2 CrO2 B Chrome tape detection switch deck B [open=Cr: close=Fe] 3 REC FWD Record tab protection status switch (forward) [open=on: close=off] 4 PHOTO B Photo sensor output (tape movement indication) 5 SOL B Solenoid supply for deck B 6 Vcc Deck / Motor supply 7 MODE B Mode switch (head engagement) [open=off: close=engaged] 8 GND M Deck / Motor ground 9 SOL A Solenoid supply for deck A 10 PHOTO A Photo sensor output (tape movement indication) 11 MODE A Mode switch (head engagement) [open=off: close=engaged] 12 L L pin for motor 13 CrO2 A Chrome tape detection switch deck A [open=Cr: close=Fe] 14 H H pin for motor

CONNECTOR 1770 DECK A & B CONTROL INTERFACE

(For Dolby B NR version only)

(For Non-Dolby version only)

1 B R/P HD L+ R/P Head left channel positive 2 B R/P HD L- R/P Head left channel negative 3 B R/P HD R+ R/P Head right channel positive 4 B R/P HD R- R/P Head right channel negative 5 ERASE HEAD Erase Head 6 GND A Erase Head ground

CONNECTOR 1730 DECK A HEAD CONNECTIONS

1 A PB HD L+ Pb Head left channel positive 2 GND A Pb Head return ground shield 3 A PB HD R+ Pb Head right channel positive

(For Double Deck versions only)

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