Sharp Mz-80b User manual

SHARP

SERVICE

.MANUAt""

.uu

....................................................

~~~~~M~1

~)

PDSM581008·MZ

•

.~

~

()

[FEATURE~

Personal

Computer

MZ-80B

Options

MZ·80EU

MZ·80I02

(Expansion Port)

(Universal

I/O

Card)

MZ-80GMK (Expansion Graphic RAM)

MZ·80FI (Floppy Disk

I/O

Card)

Optional Peripherals I

MZ·80FBK

(Expansion

Floppy

Disk)

MZ·80FB (Floppy Disk)

:J

•

The

MZ-80B. ste'pped

up

version of

the

MZ-80K,

is

a personal

computer

with

many

new

functions,

• Using a Z-80 processor (4MHz Version}

in

the

CPU,

it

is

capable

of

high

speed

data

processing.

•

It

has

a keyboard

touch

that's ideal

for

a professional

operator

and

is

equipped

with

a 10 numerical

keys

and

10

function

keys,

•

The

cassette-recorder,

using

an

electromagnetic

mechanism,

can

be

stopped/started

remotely.

Programs

and

data

can

be

recorded

automatically.

• With

the

optional

expansion

port,

1/0

card

Can

be

set

in

the

body

of

the

MZ-80B

for

peripherals

such as a

floopy

disk,

print~r,

etc.

SHARP

CORPORATION

~-.

r---------Contents---'-----------------....

MZ-BOB

Specifications. , , , , , , , , , . , , , , , , , , , , . , . _

.......

_

...

,

...

- - . .

..

1

System configuration

and

nomenclature

of

MZ-80B. , , , ,

..•.

,

....

, . - . .

..

3

Configuration

of

MZ-80B

_________________________

. . . . . . . . . .

...

5

Trouble shooting guide. _

..•

_

•.

_

.•

__

. _

••

: _

•.•

___ • • . . . . . . . . . . •

..

7

CPU board section

••..••..•.•••

_

•••••

~

•••••••

-;

•••••.••.••..•.

8

Power supply section

......

'.

'

..

.-

••

'

.............

, , , , . , ,

•••••

'

••

0.'

0'

16

Monitor

TV

section,

. , ,

...

', ,

..

,o.<:":-;"~".

,

~"':',

.

.-,

,

,",

';"~

-~'

.:::~:~~~::",,:,"~,

~<

.

c~·

20

Cassette

tape

recorder

section.

, ,

~

.•...

:;-

..

, . , "

........

'-~".

,

...

, , "

-,

Printed wiring board

and

circuit diagram

.•...•.

0"

••••••••••••

,

•••••

Disassembled view

.....•.......•...............

, . ,

..

, , , , ,

.•.

Packing method

••..

:'

•••••....••••..••.••.•.

:

••..••••.....•

OPTIONS

and

OPTIONAL

PERIPHERALS

Expansion

port

MZ-BOEU

..............

,

.....................

.

Universal

I/O

card

MZ-80102

..................................

.

Expansion graphic RAM MZ-80GMK

............................

.

Floppy disk

I/O

card

MZ-80Fl.

................................

.

Floppy disk

MZ·80F8,

Expansion floppy disk

MZ·80FBK

..............

.

Replacement

parts

list,

..

'

...

,

...

,

......

, - . ' ,

....

,

..........

.

Caution

in Service

'"

Maintain

the

safety

[]nd

protecting

ability

of

the

apparatus

after

service,

..

High voltage shall

not

be rised

to

excess specified level

so

as

to

prevent

This

apparatus

from

the

extra

X·ray

radiation.

24

29

45

51

52

55

58

61

67

70

•

• MZ-80B General

CPU

LH0080A (Z 80A-CPU) Key

Layout

Keys

92

Clock 4MHz ASCII Standard,

10

Numerical keys,

Memory

ROM

2K bytes Function keys, Cursor control keys,

Cassette

tape

deck control keys

RAM

64K bytes (dynamic RAM) Clock

function

Built-in

Editor function Cursor control; up,

down,

right, left,

Display

9"

CRT (green display)

home,

clear.

8 x 8

dot

matrix Edit key

1) Characters;

1000

Delete key

~-,--.-

--._--

----

(40

characters x

25

lines) Power supply

AC

240V

(50Hz)

2) Characters;

2000

Temperature Operating temp;

0°

to

35°C

(80 characters x 25 lines) Storage temp; _15°

to

60°C

----

1), 2): software change-over Humidity

Lower

than 80%

Cassette Standard audio cassette tape Weight Approx_ 16kg

Data transfer speed;

1800

bits/sec. .

---

_.-

Dimensions Width

45cm

Data transfer system; SHARP

PWM

Depth 52cm

Manual or Automatic control Height 27cm

Sound output 400mW max. (440Hz) _

..

--

•

CPU

Board

Section

CPU

LH0080A(Z80A-CPU) 1 pc.

Programmable

l

--

.- .

--

counter

8253

1 pc.

PlO LH0081 A (Z80A-PIO) 1 pc.

. Programmable

ROM

IPL 1 pc.

12K

bytes) !

Character generator 1 pc,

(2K

bytes) peripheral

8255

1

pc_

I

1--. interface i

RAM

Standard; 16K

RAM

32

pcs_

---

I

(64K bytes) Other IC's

40

pcs. I

Video RAM; 1 pc. (2K bytes) I

• Power Supply Section • Graphic RAM

(I)

PWB

Section

------

-

Input

AC

240V (50Hz)

~-----

Output

5V

RAM

Static

RAM;

4 pes.

18K

bytes)

----

---t------------

._J

Other IC's 17 pes.

.J

-5V

12V (stabilizing)

12V (non-stabilizing)

-

----

NOTE

Specifications

and

appearance

are

subject to

change

without

prior notice for improvement. In

such

a case, the

explanation

here may

be

a little

different

from the

product

.

-1-

-·

• Display Section

l.

General

specifications

11.

Electrical specifications

Size

9"

Video

output

40Vp-p

standard (35Vp-p

limit)

Vertical 60Hz (vertical),

lS.75kHz

(horizontal)

Resolution

Horizontal

*The

pattern

of

the

left

in

Horizontal •

the

center

of

the

picture

Frequency

must

be clear. •

P~wer

source DC

12V,

1.1

A

±1O%

Non-linearity

Horizontal;

±8% (±14% max.)

distortion

Vertical;

±8% (±12% max.)

Picture

tube

E2728B31;

9"

90°

deflection

Geometrical

Pincushion

dist.;

1%

{2%

max.}

explosion proof type

distortion

Barrel

disl.;

1% (2% max.)

Heater;

12V,

7SmA

Trapezoidal

dist.;

1%

(2% rr,3x.)

1----.

Parallelogram

dist.;'o

(2.5°

max.)

.'

IC's 2

pes.

High

voltil<;Je

Zero beam;

11.0kV

-I (1O.0kV,

min.,

Transistors 7

pes.

I

12.0kV,

max.)

----

Diodes 13

pes.

Power

su

pply

I

DC12.0V,

1.05A

(1.2A

max.)

-

Working

range

12V ±10% •

Sound

output

400mW

max. (440 Hz) Scan size

Horizontal;

10% (15% max.)

Speaker

Bern,

round

dynamiC

type

I

Vertical;

10% (15%

max.)

(32I2l

Horizontal

~-

Control

knobs

Volume, V-Hold, lock"in range I

±300

Hz

(±100Hzlimit)

Contrast,

H-Hold, Vertical [

Brightness,

Focus

lock-in

range

I

-12

Hz

(-6

Hzlimit)

~-

--

Working

440

Hz (OdB)

-10'e

to

SO°C

Audio

frequency

I

-10dB

±4dB

at

100 Hz

temperature

Characte~istic

I

-12dB

±4dB at

10kHz

-•

I

Sound

maxi- I 400mW at

440

Hz

mum

output

'-

~

-----

--

• Cassette Tape Recorder Section

--

System

PWM

recording

BiaSing DC system

5V

±

5%

Erasing

DC

system

Power

source

12V

±

5%

(stabilizing) •

9.5V'"V16.5V (Non-stabilizing) Playback 667

J1sec.

to

333

J1sec.

~-

sensitivity (standard)

Semi-

22

transistors Working

I

_10

oe

to

+40°C

conductors

13

IC,

temperature

~~

9 diodes

--

Storage

-2SoC

to

+65°e

Tape

From

C30

to

e60

,

temperature

,

---

Tape speed

4.75

cm/sec.

~-

-

Track

2-track

monaural

type

~ -

Motor

Electronic

governor

motor

(12V}

L-_~

•

I

-2-

•

The MZ·80B system and expansion

thereof

are shown

in

the

block diagram

0.1

Fig.

1.

The inside of

the

dotted

lines

is

the

constitution

of

the

MZ-808,

in

which units enclosed

in

thick-line frames are optional ones.

In

the

expansion

port,

interface cards can

be

inserted up

to

six pieces. The devices outside

the

dotted

lines are optional peripheral

devices and user's devices.

Figures 2 and 3 show the

front

view and rear view of the MZ-80B, identifying

the

parts with names.

r---------------------i

I MZ-80B

I

L

I

CRT

I

Display I

~

f I

Graphic

RAM

CG

Rom

(RAM

11

8KBI

I

'v---

(MZ-80GMKI

32KB

2KB

I I

I

Graphic

Universal

c!-

RAM

18KB

Interface

PTR,

PTP,

etc.

RAM

IMZ-SOI021 I

32KB

V-RAM

+

Character

MODEM

2KS

~

RS-232C Teletvpewriter

Boot

Rom

~

I

etc.

2KB

IEEE-4SS

1.-

IEEE-488

Standard

~~

-"

"W

Interface

I devices

CPU

°0

I

System

Bus

0.

00

ZSOA

f-'

xN

w~

Printer

t

Printer

Interface

IMZ-SOP5')

FD

Interface

1

Floppy

f- (MZ-SOFIJ Disk

I

(MZ-SOFB/FBKI

Key Board I

HD

I I I

;<-

Interface

Hard

Disk

Sound

Ir-

Cassette r

f-

MCR

l~

Mark Card

Interface

Reader

Timer

1.1-

Calor

Color

Display

Intelligent

Interface

I

Terminal

I I

I

Color

Display

---------

______________

---l

Fig_

1 MZ-80B System and Expansion o

Options

D

Future

Development

-3-

Nonglare

~

_________

+

Screen

Special

function

_____

_

Keys

Main

Key

Board

______

--:

Brightness

_______

,

Control

Sound

Volume

Control

Power

recePtacle---""

Power

Switch

---------i..----

Ground-----------J

r---------------------------------

9"

CRT

Display

r------------

Cassette

Tape

Compartment

!~~~J,~~~?i~i~~

..

-,

Cassette

tape

Counter

~0ii!C=1-.

Fig. 2

Front

View

of

MZ·80B

Fig. 3

Rear

View

of

MZ·80B

Cassette deck

~---

Control

Keys

Cursor

Control

Keys

IPL reset

switch

~---"o<,e'

Switch

I/O

Module

Access

Window

No.

1-6

• •

•I

I •

• •

The system diagram

of

the MZ-80B

is

shown

in

Fig.

4.

With the CPU and its

bus

lines

in

the center, the

memorie~

(main memory,

boot

ROM, V-RAMI, keyboard, cassette recorder, CRT display, clock, reset circuit, and I/O

port

are

arranged, showing the relations with PlO,

8225,

8253,

to

constitute

the

MZ-80B.

RESET

SWITCH

'IPL

RESET

SWITCH

FRAME

GROUND

-11-

AC

I

nPOWER SWITCH

~

1 1

POWER UNIT

POWER

TC!ITv

ONIPL

-5V

RESET GROUND

C R

E

L-.

S

0 E

T

A

Z80A

CPU

"

4>

CRYSTAL

16

£ 4MHz

OSCILLA-

MHZ'l

TOR

31.25kHz

Jl

L

E

D

'IPL

RESET ".." Initial Program Loader RESET

-5-

Main Memol)'

RAM

32k

bytes

IPL

ROM 2k bytes

".

RAM

32k

bytes

ADDRESS

SELECTOR

"r I

-,

I1

m

ADDRESS BUS

1

11

1

u:

11

IL

JI

J

~

T

LB

S

r-

HAN

Z80A-PIO

POK

4>

~

I

KEYBOARD

r--

Fig.

4 r

CHARACTER

SPEAKER

GENERATOR AUDIO .n

RoM

2K

bytes

r;::::

AMPLIFIER

11

vLj

-"

V-RAM

l-<--

, CRT

DISPLAY

-CHARACTER

-:v'

2k

bytes

I'r

OSCILLA·

S

TOR

SHIFT

E

f=4

L , REGISTER

E VIDEO GENE·

C

V·RAM

l-

T , RATOR

GRAPHIC I

------I

0

-"

8k bytes

rt

11

T

, I I

11 11

11

J1 -

=

11

11 11

11

V·RAM

=

11

P GRAPHIC II

.

11 11

, E 8k bytes

ADDRESS

BUS

R (OPTION)

I

=i~

I

II1I

11

, P

H

,....,

E 0

IH

III

v R P

r A T

L I

[)NT

BU

I 0

v / N

~

0

,

!.-

~ ~

P

SHAKE 0

8255 8253 R

.

CO

Cl

C2 T

11

--

]~~

CASSETTE TAPE CASSETTE TAPE

DECK I/O DECK

~-80B

System Diagram

I

No. I

I

No. 6

•

The system comprises four main units.

For quick solution

to

most operational difficulties, follow

the

chart below

to

find which unit

is

causing

the

problem.

Start

Power on

YES

Is

the

CPU

board normal?

YES

End

NO

N9

-7-

Repair

the

power -supply

circuit.

Repi3ir

the

monitor TV.

Repair

the

CPU

board.

Repair the cassette

recorder.

•

The

CPU

b~ard

is

composed of the following six blocks.

When

it malfunctions, first locate which block

is

concerned

with the malfunctions, and next try to check for its corresponding circuits; the wiring diagrams of every block will

be

shown separately.

CPU

inoperative

Display

block

Cassette

recorder

block

Keyboard

block

Audio

block

NO

Clock

block

NO

YES

<e

noperative

YES

immediately

after

>------0-1

power

ON,

NO

Check

RAM

and its

peripheral

circuits

{by

usinfj

RAM

checked,

Check

video

RAM

circuit.

Check IC23

(8255)

and its

peripheral parts,

Check

IC24

(LH0081A)

and

its

peripheral parts.

Check IC23

(8255)

and

its

peripheral

P<lrts.

----'

Check

IC19

(8253)

and its

peripheral parts,

Check

memory

circuit

and

its

peripheral parts,

•

Checki~g

rnetl1ods()f~~h

circuit -,,;

"I,

","

..

,,,'

"_

•

",.

'"

_

:.l.C.By.tbuChinglC package

by

fingers:c .

.•.

Ifthey

seem too

hot

by

heat

gene~atiori;

2.

I(:::--j{ defective" le

'Idad

'is

'hea~'y

'or

~'~mporients

are

~ouc~~-

'"each'

other

(ROM

and V·RAM are

.

ex.~mpted

f;~m

this checking).

e,

If.-

a circuitry state changes to,

an~ther;

Sold~ring

is-

poor, socket contact

is

impro'per or printed-

wiring

is

erroneous.

By

using a synchroscope:

•

If

the

relation between input and

output

of TTL

IC

is

illogical, this means defe.etive

IC

gate.

• Check if the voltage of TTL

IC

is

as

specified: Highle,;el; over 2.4V"Low level; below O

..

5V.

• When the signal'is between the high and low levels,

is

~here

circuit t?uching or

!C

malfunction?

-8-

,

• Display Block

DO

-

I Bus driver

07

-

AD

Al

1

0

cso

SOC

VGAT

Whole

rever

H

E

se

~

I Problem

CSOO

No

sync. signal

I

No

video signal

wFi-

\

/

Characters displayed

but

position

abnormal

\

Character generator Vide

-/

Shift

register Sync

/

';".,

o

signal

. signal

'----

-

Video

RAM

L--

lr

Oscillator

V Oisplay

controller

f------

circuit

Address

selector

~

I

Block Diagram around

Video

RAM

....

, Check Point

.

Is

the correct signal present at pins

12

and

13

of

IC36 ?

Yes:

Check IC36.

No: Check IC42

and

IC43 and around them.

(In particular, check

if

the

input

of

8MHz, 16MHz

and

other

clocks are correct (Wave

form

is

shown

on

page

15.))

Is

pin 16

of

IC42 at a high

level'

No: Check IC23.

Yes:

Proceed

to

the

following.

:

Is

a video

signal

present at

8 of

IC46?

Yes: Check IC31, IC33 and IC36.

No: Check IC42 and IC43 and around them.

(In particular, check if the input of

8MHz

and

16MHz

and

other

clocks are correct (Wave

form

is

shown on

page

15.))

Is

the signal at pins 3,

6,10

and

13

of

IC37, IC38

and

IC39

correct?

Yes:

Check the

address

of

IC41

and

the signals

of

IC37,

38

and

39 connected to

it.

-9-

Position

is

correct

but characters

are

abnormal

Displayed

characters

are

abnormal

• Keyboard Block

D7

I

DO

MI

Al

AD

-\

-----/

B7

I

BD

LHO

A4

081A

A3

I

PlO

AD

~

I

INT

lED

Does

not

accept key entry.

No: Check IC 37, 38, 39,

42

and

43.

Check the common line

of

IC22, IC41

and

IC44

and

around the IC22.

Check

A,

-

Ao

and

D,

-

Do

of

1C45

and

IC42.

Key strobe Key board

cancelling.signal

Decoder

Block Diagram around Keyborad

,Point

Is

key strobe present?

Yes:

Check keyboard, IC24

and

around it.

No: Check IC25, IC27, IC28. IC29

and

IC36.

-10

-

If

they are normal, check

IC24

and

around it.

A3

A2

Al

AO

Peripheral

86

interface

85

18255) B4

C7

C6

C5

C4

1--

-,

b STOP

I

b

I

p

I

PNL

BLKl

8LK2

P

RDATA

P

TREADY

b

WREADY

I

P

WDATA

P

WRITE

bREW

I

o

OPEN

I

L

_____

J

Block

Diagram around

the

Cassette

Condition

~

.

--T:-Ch~Ck

Point

,I,:

Load

is

not

possible.

Is

there

a signal

from

6

of

le

26?

YES.

Check IC23.

NO.

Check

IC26.

Save

is

not

possible.

Is

there

a signal

from

10

of

IC23?

YES.

Check

IC26.

NO:

Check

IC23.

Motor

does

not

turn.

Check

IC23.

MOtor

does

nOt

stop.

Check

IC23.

-

11

-

For cassette

• Clock!Audio Block

07

I

DO

,

-I

IRO Programmable

counter

18253)

CS

GO

Al

Gl

AD

-cc

',,'

"

-~;

troblem,.

.,;,

•..

Clock

tunction

is

abnormal.

Audio

output

is

abnormal.

~

31.25kHz

07

I

DO

IRO

IWR

CS

Peripheral

interface

182551PC2

Counter

#0,

#1,

eset signal

,

Al

AD

RESET

Block Diagram around

Clock!

Audio

Block

.'

....

' " Check Point

-

Is

there a 31.25kHz

signal

present

at

9 of

IC19 ?

Yes:

Check IC19 (8253)

and

around

it.

No: Check IC42

and

around it.

Is

an

output

signal

present at pin 4

of

IC31?

Audio

output

.>~;

Yes: Check amplifier section

in

the display board.

No: Check IC23, IC31

-12

-

• Memory/Reset Circuit Block

AO

-

A13

Data selector

RAM

block

Problem

Picture

"panic"

when

power

is

on.

Abnormal action

immediately after end

of

program due to

BOOT

program

Error

when program

is

in

RAM

AO--

A10

ROM block

Memory/Reset Circuit

Memory control

circuit

07

DO

,Check Point

CPU

control

bus

A15

1

Al2

Does

pin 26

of

I

C3

go

from

High

to

Low

when the BOOT

reset

SW

is

pushed?

No: Check IC33

Yes: Proceed the following.

Is

pin 15

of

IC2

High?

No: Check IC34

Yes:

Check address line

AO

-

A15

(ICB, IC10)

Data line

DO

-

07

(ICll)

Control line (lC7)

IC2, ICS, IC14, IC1B

Is

pin 15

of

IC2 at

Low

Level?

Yes: Check IC34

No: Check IC2

Check RAM

-13

-

.. How

to

Use

RAM CHECKER

Insert

RAM

CHECKER into BOOT

ROM

socket and turn

the

power on. Then

RAM

TEST·1 and

RAM

TEST-2 will automatically

be

carried

out

from

RAM

address

$0000

to

address $F FFF

as

shown below

and.the tested results will

be

displayed.

The checker tests

the

store by dividing

it

into two parts of addresses $0000

to

$7FFF

and

$8000

to

$FFFF.

Example

of

the

test results (When all RAM'. are normal)

Check

RAM

(l)

block, 16K bytes,

RAM

(ll) block 16K bytes

1)

RAM

TEST·1

A writelread test of data $00 and

$FF

is

carried

out

from address

$0000

to

$FFFF,

and

if

an error

occurS ERROR

is

displayed

in

the

16K bytes unit.

Example

of

above mentioned display

IOOOOi'::

O.

K. I

....

· Result of writehead test from address

$0000

to

$3FFF

is

normal.

,_J

_:.

'~11'

Example of display when ERROR appearS.

IER:23,5B:00,

01

1...........

Write

in

data was

$00

at

address

$2358

but

read·out data

was

$01.

An

error

is

displayed by

the

address

number

at

which

the

error takes place, and

the

excution

of

check

is

stopped

at

the

address.

2)

RAM

TEST·2

Write/read

test

is

carried

out

with

the

following items_

al

Write-in data $00 (From address $0000

to

$7FFF)

b)

Write-in data

$FF

(From address $0000

to

$7FFF)

c)

Write·

in

data

$00

(From address

$7FFF

to

$0000)

d)

Write-in data

$FF

(From address

$7FFF

to

$0000)

e)

Write-in data

$FO

and

$OF

entered alternately (From address $0000

to

$7FFF

and vice verSa.)

f)

Write·in data

$00

(From address

$8000

to

$FFFF)

g)

Write-in data

$FF

(From address

$8000

to

$FFFF)

hi Write-in data

$00

(From address

$FFFF

to

$8000)

i)

Write-in data

$FF

(From address

$FFFF

to

$8000)

j) Write-in data

$FO

and

$OF

alternately (From address

$8000

to

$FFFF

and

vice

versa)

Example

of

ERROR in

RAM

TEST·2

, .RAM TEST-2

00

FF

00

ER·23FF·01

Test results of

a)

and

b)

were normal

but

in

c), although data

$00

was

written in address $23FF, read-out

data

was

$01. When ERROR

is

displayed

in

the above mentioned

RAM

TESTs, decide which

RAM

block

is

bad according

to

the

memory

address where

the

error occurs. Then

you

can decide which

RAM

is

bad in the

RAM

block where

the

error occurs by

the

bytes

pattern

of

the

write-in data and reao-out data.

In

the

above

example, you can tell

that

it's

RAM

(I) block by

$23FF

and

that

RAM

1

is

bad because write-in data

is

$00

but

read-out

data

is

$01.

(See

Fig.

next)

t~'

06 05

04

03 02

01

DO

-------

Write·in date

$00

0 0 0 0 0 0

~Error

Read-out data

$01

0 0 0 0 0 0

:,:

':

l:

:

..

i

to

occur

-14-

RAM

III

RAM

121

RAMlml

RAM

IIYI

D7

~'SHARP81

P

16[

PSHAR

24[

P

321

D6

P

71

P

151

P

231

P 311

D5

P 61 P

14/

P

22[

P 30[

D4

P

51

P

131

P

211

P

291

D3

P

4[

P

121

P 201 p 281

D2

P

3[

P

11[

P 19 1 P

271

D1

P 21 P

101

P 18 1 P 261

DO

~

1 I P

91

P 171 P 251

•

Waveforms

of

CPU

Board

23 of IC42

22 of IC43

20

of IC42

20

of IC43

-

--

lSMHz

8MHz

4MHz

19

of

IC42

21

of

IC42

21

of IC43

19

of IC43

------

~

-

'-----

2MHz lMHz lMHz

10

o~

IC42

F'in

12 of IC36 Pin 7 of IC42

J U I

-

,---

16.64ms

64", 64",

Pin 9 of IC19

3L251(Hz

-

15-

~

AC

240V

50Hz

~

•

Filter circuit

r--

Voltage

stab;';,er

c;rcu;t

:

Transformer L Rectifier

circuit 1

I-- I--

f-

Voltage

stabilizer circuit

Rectifier

circuit

\

Voltage stabiliz.er circuit

Rectifier

circuit 1

Block Diagram of Power Supply Circuit

•

..

•

----.--. --------'_._ •

_____

•

______

.0

____

-

__

..___________

+12V

r-

+12V

E

+5

~

-CO

-5V

+12V

+5V

'-

E

..

•

• Trouble Shooting Chart

Problem (1)

No

voltage

at

any

output

terminal.

Check primary circuit which includes

the

transformer.

Problem

12)

Problem (3)

No.

-5V.

Is

approx.

11

V

present

on

both

ends

of

C201?

Check

IC201,

C203

aod R201,

No

+12V.

NO

Chlt~k

t101,

F201,

D201,

C201 and

C202.

Check

primary

circuit

which includes

T101.

Is

voltage

at

the

NO

other

output

~~~------------------------------------------------

__

___

terminals

normal?

Is

approx. 24V

When

A309

is

open,

does

a

O.2Vpp

appear

at

12of1C301,

Check

0301,

Q302

and

smoothing

circuit,

NO

Check

IC3Ql

and

circuit

of

IC301.

-17

-

Check

F301,

nOl,

D301.

C309. C301,

C302

and

C304.

Check

primary

circuit

which

includes

Tl01.

Problem (4) No

+5V,

Is

voltage at the

other output

terminals normal?

IS8pprox.14V

present at pin

15

of

IC4017

NO

When

R405

is

NO

open, does O.2Vpp

appear'>='---

____

~

at

pin 12

of

IC401?

Check

Q401,

0402

and smoothing

circuit

Problem (5)

-5V

is

abnormally high.

Check IC201

Problem (6)

+12V

is

abnormally high.

Check 1C401 and

circuit

of

IC401

Check

0301,

0302

and IC 301.

Problem (7)

+5V

is

abnormally high.

Check

0401,

0402

and IC401.

Check F401, T101,

D401,C412,C401

-C404, C407

Check

primary

circuit which includes

T101.

Sharp MZ-80B User manual

Popular Desktop manuals by other brands