Akai AM 47 Service Manual

Page 2

* SAEETY INSTRUCTIONS

PRECAUTIONS DURING SERVICING

1. Parts indentitied by the-A (a) symbol are critical for
safety. Replace only with parts number specified

2. in addition to safety, other parts and assemblies are
specified for conformance with such regulations as
those applying to spurious radiation.

These must also be replaced only with specified re-
placements. -
Examples: RF converters, tuner units, antenna selector
switches, RF cables. noise blocking capacitors, noise
blocking filters, etc.

3. Use specified internal wiring. Note especially:

1) Wires covered with PVC tubing
2) Double insulated wires
3) High voltage leads

4. Use specified insulating materials for hazardous live

parts. Note especially:

1) Insulation Tape

2) PVC tubing

3) Spacers (Insulating Barriers)

4) Insulation sheets for transistors

5) Plastic screws for fixing micro switch (especially In
turntable)

5. When replacing AC primary side components (transfo-
mers, power cords,noise blocking capacitors, etc),
wrap ends of wires securely about the terminals before
soldering

sweet?

6. Observe that wires do not contact heat producing parts
(heatslnks,oxide metal film resistors, fusible resistors,
etc.).

* INFORMATION

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

8. Also check areas surrounding repaired locations.

9. Use care that foreign objects (screws, solder,droplets,
etc.) do not remain inside the set.

SAFETY CHECK AFI'ER SERVICING

Alter servicing, make measurements of leakage-current
or resistance in order to determine that exposed parts
areacceptably insulated irom the supply circuit.

The leakage-current measurement should be done be-
tween accessible metal parts (such as chassis, ground
terminal, microphonejacks, signal-input/output connec-
tors, etc.) and the earthground through a resister oi 1500
ohms paralleled with a 0.15 uF capacitor, under the unit's
normal working conditions. The leakage~current should be
less than 0.5 mA rms AC.

The resistance measurement should be done betweenac-
cessible exposed metal parts and power cord plug prongs
with the power switch (it included) "ON". The resistance
should be more than 2.2 Mohms.

SYMBOLS FOR PRIMARY DESTINATION

Alphabet indicates the destination of the units as listed
below.

S P
USA
UK
Canada
Eu e

Destinations

J an
Australia
German

Custom version

SERVICE MANUAL

Page 13

NOMkWN-k

AKAI

MODEL AM-37, 47

SCHEMATIC DIAGRAMS
AND PC BOARDS

TABLE OF CONTENTS

. INFORMATION OF IC ................................................................
. BLOCK DIAGRAM ...................................................................
. MAIN AMP & CONNECTION DIAGRAM ........... .
. MAIN AMP AND OTHER PC BOARDS .......................... > ......................
. CONTROL 8: INPUT SCHEMATIC DIAGRAM ..........................................
. CONTROL AND OTHER PC BOARDS . . . .
. INPUT PC BOARD ...................................................................