Akai GX 75 Service Manual

Page 2

*SAFETY INSTRUCTIONS

PRECAUTIONS DURING SERVICING

1. Parts identified by the : (*) symbol parts 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 selec-
tor 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 microswitch (especially in
turntable)

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

seats?

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

* INFORMATION

7. Check that replaced wires donot contact sharp edged
or pointed parts.

8. Also check areas surrounding repaired locations.

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

SAFETY CHECK AFTER SERVICING

After servicing, make measurements of leakage-cu rrent
or resistance in order to determine that exposed parts
are acceptably insulated from the supply circuit.

The leakage-current measurement should be done be-
tween accessible metal parts (such as chassis, ground
terminal. microphone jacks, signal-input/output con-
nectors, etc.) and the earth ground through a resister of
1500 ohms paralleled with a 0.15 uF capacitor, under
the units normal working conditions. The leakage-cur
rent should be less than 0.5 mA rrns AC.

The resistance measurement should be done between
accessible exposed metal parts and power cord plug
prongs with the power switch (ifincluded) ON". The
resistance should be more than 2.2 Mohms.

SYMBOLS FOR PRIMARY DESTINATION

Alphabet indicates the destination of the units as listed
below.

_ Symbols Principal Destinations

USA

UK

Canada

LE Europe (except UK)
Japan
Australia
W. Germany only
Universal Area
Custom version

SERVICE MANUAL

VOLTAGE CONVERSION
(I Model only]

Before connecting the power cord. Set the VOLTAGE
SELECTOR located on the rear panel with a screw
driver so that the correct voltage is indicated.

VOLTAGE l
SELECTOR '
v

Page 8

4-4. REMOVING THE CAM MOTOR AND
CAM BELT

1) Remove the motor block from the mechanism block.
(See section 4-3, Removing the motor block)

2) Disconnect the two cam motor lead wires.

3) Remove cam motor base screws @ and @ from the
motor block. (See Fig. 4-7.)

4) Remove the cam belt and operation pulley from the
cam motor block which has just been removed.

5) Remove cam motor securing screws© and@. (See
Fig. 4-8.)

6) To reassemble, perform the above steps in reverse
order.

MOYO R BLOCK

Fig.4-7

CAM MOTOR

OPERATION
FULLY

Fig. 4-8

76AM MOTOR

-cAM BELT

SERVICE MANUAL

4-5. REPLACING THE HALL ELEMENT

1) Remove the motor block from the mechanism block.
(See section 4-3, Removing the motor block")

2) Remove motor PCB block securing screws ©, @ and
© and take out the motor PCB block. (See Fig. 4-9.)

3) Remove the solder from the Hall element. Remove
the Hall element from the motor circuit board.

4) When attaching a replacement, connect the protrud-
ing portion of the Hall element to the circuit board.
(See Fig. 4-10.)

5) To reassemble, perform the above steps in reverse
order.

MOTOR PCB BLOCK

Fig. 4-9

MOTOR PCB

HALL
ELEMENT

MOTOR PC 5

Moron PCB BLOCK

Fig. 4-10