AIWA NSXMA545
Service Manual

NOTE 1. Forced
When across secondmy In order

ON

BEFORE

STARTING ofelectrolytic

REPAIR capacitor ofpower
relay circuit

discharge
is going

supply
in the cord

block
power supply block, Ifrepair electric isattempted potential is kept charged the

repair

to be attempted capacitors (CIO1,

in the 102)

set that even

uses though

theelectrolytic defect to prevent can the

ACpower

is removed.

inthiscondition,

occur. secondary trouble, perform the following measures before starting repair work.

Discharue -.
Remove Connect hasclips wire

wocedure
the AC power cord. resistor Connect at an end theother of lead wire that lead

1,,,
II MAIN C.B

a discharging at both ends.

endofthe

to metal the (+) the

chassis. other side same end (+VH) end (-) seconds) across a multimeter C101 and C102 has decreased of the of discharging (For two resistor seconds) resistor in the as step same to the

Contact positive Contact @) to the way. Check 1V (For

C101.

of the side

discharging of C102

negative two

(-VH)

that or less

voltage using

or an oscilloscope.
I

6

Select

a discharging

resistor

referring

to the

following

table.

Fig-1

Charging

voltage

(V)

Discharging Rated power (W) Parts number resistor 100 220 (Q) 3 5 87-AOO-247-090 87-AOO-232-090

(Clol,
25-48 49-140

102)

Note:

The

reference

numbers

(C101, charging

C102)

of the

electrolytic on schematic

capacitors diagram

can

change

depending the

on the discharging

models. work.

Be

sure

to check

the

reference

numbers

of the

capacitors

before

starting

2.

Check
Be sure

items
to check that

before
the the following

exchanging
items before

the

MICROCOMPUTER
the MICROCOMPUTER. Exchange the MICROCOMPUTER after

exchanging is surely

confirming

MICROCOMPUTER

defective.

2-1.

Regarding
When correctly. the HOLD the the

the
HOLD When terminal

HOLD
terminal this

terminal
(INPUT) is �L�, exchange. is not the

of the
of the the

MICROCOMPUTER
is �H�, be turned the on. MICROCOMPUTER Therefore, be sure is judged to check the to be operating terminal voltage of

MICROCOMPUTER main power cannot

terminal before

When

MICROCOMPUTER that triggers

defective, detection

the

HOLD circuit

terminal on the

can MAIN

also

go

�L� that

when sets the

the

POWER

AMPLIFIER to �L�.

has

any

abnormalities

abnormality

C. B.

HOLD

terminal

q

Good

or no good
on the that AC the

judgement
main main power. power

of the

MICROCOMPUTER

Turn Confirm not. When

is turned

on

and

the

HOLD

terminal

of the

MICROCOMPUTER

keeps

the

�H�

level

or

the

HOLD

terminal

is �L�

level,

the

abnormality

detection

circuit

is judged

to be working

correctly

and

the

MICROCOMPUTER

is judged

to be good.

�

.�

.�
FRONT

.
C.B

( ; I

r
. ,

.�. � .�-�
MAIN C.B
(

.�-�

I
PIN101 MICROCOMPU~R & o �

I
CON601

In

some

models,

it is PIN

@.

@

OVER

LOAD

DET

POWER

AMP

POWER

AMP

POWER PIN number is different upon microprocessor. .� -�. .� .�. � .�. �.

SUPPLY

depending �.�
I

�-

-

Fig-2-1

�5�