Sony bm 880 service manual

Page 1

SERVICE MANUAL

BM-880

US Model
Canadian Model
AEP Model

UK Model

E Mode/

Tape
Recording system

Tape speed
Fast winding lime
Frequency response

Speaker

Power output
input

Output

Model Name Using Similar Mechanism

NEW

Tape Transport Mechanism Type

MB-880-58

SPECIFICATIONS

(WW (normal position Iype)
rack 2-channel monaural
(L channel for electronic index signals, R channel lor sound signals)
2.4 cmls (5/I6 Ill/S], 1.2 cmls (IS/32 inls)
Approx. 1 min. 50 sec. (2.4 cmls) wilh Sony microcassexte MOGOBM
200 - 4000 Hz (at 12 cmls)
200 - 6.000 H2 (at 2.4 cmls)
Approx 57 cm (2/4 inches) dla.
350 mW (at 10% distortion)
TELEPHONE PICKUP (minijack)
SenSlIlVIIy 0.2 mv
Input impedance 10 kohms
EARPHONE (minljack)
for Baaooohm earphones

CONTROL UNIT connector

Power requirements

Power consumption
Dimensions

Weight
Supplied accessory

for HU-BO or FS-75
9V DC
DC IN 9v jack accepts the supplied AC power adaptor for use on
I2DV AC. 60Hz (US, Canadian model)
220V AC, 50HZ (AEP, E model)
240V AC, SOHZ (UK model)
14W (US, Canadian model) (with the supplied AC power adaptor)
13w (AEP, UK model) (with the supplied AC power adaptor)
Approx. 200x70><245rnm (w/h/d) (7'/,><2/.><9/; inches)
including proiectmg parts and controls
Approx. 1.4kg (3 lb 2 oz)
AC power adaptor (A0980) (1)

Design and specifications subject to change Without nolce.

SAFETY-RELATED COMPONENT WARNING

COMPONENTS IDENTIFIED BV MARK A OR DOTTED
LINE WITH MARK A ON THE SCHEMATIC DIAGRAMS
AND IN THE PARTS LIST ARE CRITICAL TO SAFE
OPERATION. REPLACE THESE COMPONENTS WITH
SONY PARTS WHOSE PART NUMBERS APPEAR AS
SHOWN IN THIS MANUAL OR IN SUPPLEMENTS PUB-
LISHED BY SONY.

ATTENTION AUCOMPOISANT AYANT RAPPORT
A LA SECURITE!

LES COMPOSANTS IDENTIFIES PAR um: MARQUE A
sun LES DIAGRAMMES scnéMAnouss at LA LISTE
DES PIECES som CRITIQUES POUR LA sécunné
DE FONCTIONNEMENT. NE REMPLACER ces com.
POSANTS ous PAR mas PIECES sonv DONT LES
NUMEROS som- DONNES DANS cs MANUEL ou
DANS LES SUPPLEMENTS PUBLIES PAR souv.

DICTATIIR/ ANSBRIBER

SONY

Page 2

BM-880

TABLE OF CONTENTS

Section Ltle fig
1. SERVICING NOTES
Note for Repairing .............................. 3
LCD Check Method .............................. 3
Pinch Roller Cleaning Mode ........................ 3
Microcomputer yPD75312GF»136»3B9 (lC113) ........ 4
2. GENERAL
Features... ...11
Precautions ................................... 11
Operation Flow Chart ............................ 12
Location and Function of Controls .................. 13
Preparation ................................... fl r .15
Dictation .............................. . . .16
Transcription .................................... 19
Erasing .....
Alarm System .................................... 22
Examples of Dictation and transcription ............ 23
Other Convenient Functions ........................ 24

Section Title Page
3. MECHANICAL ADJUSTMENTS .................. 25
4. ELECTRICAL ADJUSTMENTS .................... 26
5. DIAGRAMS

5-1. Semiconductor Lead Layouts ...... .

5-2. Printed Wiring Boards .......................... 31
5-3. Schematic Diagram .............................. 35
6. EXPLODED VIEWS

6-1. Cabinet Section ................................ 39
6-2. Mechanism Deck Section (1) .................... 40
6-3. Mechanism Deck Section (2) .................... 41
7. ELECTRICAL PARTS LIST ...................... 42

SAFETY CHECK-OUT

After correcting the original service problem,
perform the following safety check before releasing
the set to the customer:

Check the antenna terminals, metal trim, metallized
knobs, screws, and all other exposed metal parts for
AC leakage. Check leakage as described below.

LEAKAGE TEST

The AC leakage from any exposed metal part to
earth ground and from all exposed metal parts to any
exposed metal part having a return to chassis, must
not exceed 0.5 mA (500 microampers). Leakage
current can be measured by any one of three
methods.

1. A commercial leakage tester, such as the
Simpson 229 or RCA WT-54OA. Follow the
manufacturers instructions to use these instru-
ments.

2. A battery-operated AC milliammeter. The Data
Precision 245 digital multimeter is suitable for
this job.

3. Measuring the voltage drop across a resistor by
means of a VOM or battery-operated AC volt-
meter. The limit indication is 0.75 V, so
analog meters must have an accurate low-
voltage scale. The Simpson 250 and Sanwa
SH-63Trd are examples of a passive VOM that
is suitable. Nearly all] battery operated digital
multimeters that have 3 2V AC range are
suitable. (See Fig. A)

To Exposed Metal
Parts on Set

I-l
0.15M L 1.5/42 /

._I

A C
voltmeter
I0, 75 V)

Earth Ground

Using an AC voltmeter to check AC leakage.

Fig. A.