AIWA NSXHMT75 - Service Manual Immediate Download

SERVICE MANUAL

NSXHMT75

SYSTEM

CASSEIVER

REMOTE

CONTROLLER

CXNHMT75

COMPACT DISC/

STEREO CASSETTE RECEIVER

BASIC TAPE MECHANISM : 2ZM-3 MK2 PR4NM

BASIC CD MECHANISM : AZG-1 ZD3RDM

NSX-HMT75 U

S/M Code No. 09-003-425-9R1

REVISION

· This Service Manual is the "Revision Publishing" and replaces "Simple Manual"

(S/M Code No. 09-003-425-9T1).

· If requiring information about the CD mechanism, see Service Manual of AZG-1,

(S/M Code No. 09-001-335-3N8).

SPEAKER

SXNAJ72

SX-R275

SX-C605

RCZAS05

SPECIFICATIONS

REF. NO

PART NO.

KANRI

DESCRIPTION

NO.

ACCESSORIES LIST

8A-NFU-903-010

IB,U(ESF)M

8Z-NFV-702-010

RC UNIT,RC-ZAS05

87-006-225-010

ANT,LOOP ANT NC2

87-043-115-010

FEEDER-ANT,FM

· Design and specifications are subject to change without notice.

· Dolby noise reduction manufactured under license from Dolby Labo-

ratories Licensing Corporation.

· "DOLBY", and the double-D symbol

are trademarks of Dolby

Laboratories Licensing Corporation.

· The word "BBE" and the "BBE symbol" are trademarks of BBE

Sound, Inc.

· Under license from BBE Sound, Inc.

PROTECTION OF EYES FROM LASER BEAM DURING SERVICING

VAROITUS!

Laiteen Käyttäminen muulla kuin tässä käyttöohjeessa mainit-

ulla tavalla saattaa altistaa käyt-täjän turvallisuusluokan 1 ylit-

tävälle näkymättömälle lasersäteilylle.

VARNING!

Om apparaten används på annat sätt än vad som specificeras i

denna bruksanvising, kan användaren utsättas för osynling

laserstrålning, som överskrider gränsen för laserklass 1.

Caution: Invisible laser radiation when

open and interlocks defeated avoid expo-

sure to beam.

Advarsel:Usynling laserståling ved åbning,

når sikkerhedsafbrydere er ude af funktion.

Undgå udsættelse for stråling.

CAUTION

Use of controls or adjustments or performance of procedures

other than those specified herein may result in hazardous

radiation exposure.

ATTENTION

L'utilisation de commandes, réglages ou procédures autres que

ceux spécifiés peut entraîner une dangereuse exposition aux

radiations.

ADVARSEL!

Usynlig laserståling ved åbning, når sikkerhedsafbrydereer ude

af funktion. Undgå udsættelse for stråling.

This Compact Disc player is classified as a CLASS 1 LASER

product.

The CLASS 1 LASER PRODUCT label is located on the rear

exterior.

This set employs laser. Therefore, be sure to follow carefully the

instructions below when servicing.

WARNING!

WHEN SERVICING, DO NOT APPROACH THE LASER EXIT

WITH THE EYE TOO CLOSELY. IN CASE IT IS NECESSARY TO

CONFIRM LASER BEAM EMISSION. BE SURE TO OBSERVE

FROM A DISTANCE OF MORE THAN 30cm FROM THE

SURFACE OF THE OBJECTIVE LENS ON THE OPTICAL

PICK-UP BLOCK.

CLASS 1

KLASSE 1

LUOKAN 1

KLASS 1

LASER PRODUCT

LASER PRODUKT

LASER LAITE

LASER APPARAT

Precaution to replace Optical block

(KSS-213F)

1) After the connection, remove solder shown in

the right figure.

Body or clothes electrostatic potential could ruin

laser diode in the optical block. Be sure ground

body and workbench, and use care the clothes

do not touch the diode.

NOTE ON BEFORE STARTING REPAIR

Charging voltage (V)

Discharging

Rated power (W)

Parts number

(C101, 102)

resistor (

)

25-48

100

87-A00-247-090

49-140

220

87-A00-232-090

Note: The reference numbers (C101, C102) of the electrolytic capacitors can change depending on the models. Be sure to check the

reference numbers of the charging capacitors on schematic diagram before starting the discharging work.

2. Check items before exchanging the MICROCOMPUTER

Be sure to check the following items before exchanging the MICROCOMPUTER. Exchange the MICROCOMPUTER after confirming

that the MICROCOMPUTER is surely defective.

2-1. Regarding the HOLD terminal of the MICROCOMPUTER

When the HOLD terminal (INPUT) of the MICROCOMPUTER is "H", the MICROCOMPUTER is judged to be operating correctly.

When this terminal is "L", the main power cannot be turned on. Therefore, be sure to check the terminal voltage of the HOLD

terminal before exchange.

When the MICROCOMPUTER is not defective, the HOLD terminal can also go "L" when the POWER AMPLIFIER has any

abnormalities that triggers the abnormality detection circuit on the MAIN C. B. that sets the HOLD terminal to "L".

· Good or no good judgement of the MICROCOMPUTER

Turn on the AC main power.

Confirm that the main power is turned on and the HOLD terminal of the MICROCOMPUTER keeps the "H" level or not.

When the HOLD terminal is "L" level, the abnormality detection circuit is judged to be working correctly and the

MICROCOMPUTER is judged to be good.

1. Forced discharge of electrolytic capacitor of power supply block

When repair is going to be attempted in the set that uses relay circuit in the power supply block, electric potential is kept charged across

the electrolytic capacitors (C101, 102) even though AC power cord is removed. If repair is attempted in this condition, secondary defect

can occur.

In order to prevent the secondary trouble, perform the following measures before starting repair work.

Discharge procedure

Remove the AC power cord.

Connect a discharging resistor at an end of lead wire that

has clips at both ends. Connect the other end of the lead

wire to metal chassis.

Contact the other end of the discharging resistor to the

positive (+) side (+VH) of C101. (For two seconds)

Contact the same end of the discharging resistor as step 3

to the negative (-) side (-VH) of C102 in the same way.

(For two seconds)

Check that voltage across C101 and C102 has decreased

to 1 V or less using a multimeter or an oscilloscope.

Select a discharging resistor referring to the following table.

MAIN C.B

D101

C101

C102

In such a case, check also if the POWER AMPLIFIER circuit or power supply circuit has any abnormalities or not.

2-2. Regarding reset

There are cases that the machine does not work correctly because the MICROCOMPUTER is not reset even though the AC power

cord is re-inserted, or the software reset (pressing the STOP key + POWER key) is performed.

When the above described phenomenon occurs, it can lead to wrong judgement as if the MICROCOMPUTER is defective and to

exchange the MICROCOMPUTER. In such a case, perform the forced-reset by the following procedure and check good or no

good of the MICROCOMPUTER.

1 Remove the AC power cord.

Short both ends of the electrolytic capacitor C113 that is connected to VDD of the MICROCOMPUTER with tweezers.

Connect the AC power cord again. If the MICROCOMPUTER returns to the normal operation, the MICROCOMPUTER is

good.

Note: The reference number or MICROCOMPUTER pin number of transistor (Q110) and electrolytic capacitor (C113) can change depending

on the models. Be sure to check the reference numbers on schematic diagram before starting the discharging work.

2-3. Confirmation of soldering state of MICROCOMPUTER

Check the soldering state of the MICROCOMPUTER in addition to the above described procedures. Be sure to exchange the

MICROCOMPUTER after surely confirming that the trouble is not caused by poor soldering but the MICROCOMPUTER itself.

Fig-2-2

MICRO-

COMPUTER

MICR

OCOMPUTER

FRONT C.B

VSS

VDD

C113

Short with tweezers.