AIWA NSX-A909
Service Manual

NOTE
1. Forced
When across

ON

BEFORE

STARTING
of electrolytic

REPAIR
capacitor

discharge
repair is going

of power
relay circuit

supply

block
supply block, If repair electric potential is kept charged the

to be attempted capacitors

in the set that uses 102) even though

in the power cord

the electrolytic defect to prevent

(Cl 01,

AC power

is removed.

is attempted

in this condition,

secondary In order

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

Discharge
Remove Connect hasclips lead wire

procedure
the AC power a discharging at bothends. to metal the other (+) side the same cord. resistor Connector chassis. end (+VH) end of the discharging of C101. (For resistor two to the at an end of lead theotherend wire of the that

I I

II

II

MAIN C.B

Contact positive Contact

seconds) as step

of the discharging (-VH) of C102

resistor

@) to the negative way. Check (For that two

(-) side

in the same

seconds) across CIO1 and C102 has decreased 6 L @

voltage using

1 V or less

a multimeter

or an oscilloscope.

Select

a discharging voltage

resistor
(V)

referring
Discharging

to the following

table.

Fig-1

Charging

Rated power (W) (Clol,
25-48

Parts

number

102)

resistor 100

(Q)

3 5 C102) of the electrolytic on schematic capacitors diagram

87-AOO-247-090 87-AOO-232-090 can change before depending on the models. work. Be sure to check the

49-140 Note: The reference numbers

220 (C101,

reference

numbers

of the charging

capacitor

starting

the discharging

2.

Check
Be sure confirming

items
to check that

before

exchanging
items before

the

MICROCOMPUTER
the MICROCOMPUTER. Exchange the MICROCOMPUTER after

the following

exchanging is surely

the MICROCOMPUTER

defective.

2-1.

Regarding
When

the HOLD
terminal this

terminal
(INPUT) is �L�,

of the MICROCOMPUTER
of the MICROCOMPUTER the main power cannot is �H�, be turned the MICROCOMPUTER on. Therefore, be sure is judged to check to be operating voltage of

the HOLD When terminal

correctly. the HOLD When

terminal before

the terminal

exchange. is not defective, the abnormality the HOLD circuit terminal can also go �L� when sets the POWER AMPLIFIER to �L�. has any

the MICROCOMPUTER that triggers

abnormalities

detection

on the MAIN

C. B. that

the HOLD

terminal

q

Good

or no good

judgment
power. power

of the MICROCOMPUTER

Turn

on the AC main that the main

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.

In some MICROCOMF a I +

models,

it is PIN

@.

8= 8

OVER

LOAD

DET

POWER

AMP

I
DC DET POWER AMP ,~

-? depending �.�

upon

microprocessor.

t

.�.

�.

I J

1 11==��
I-.

i

-.-.

Ill

-._.

_._..

Fig-2-1

-4-