Sharp MZ-80P5 User manual

SHARP
SERVICE MANUAL
PDSM281 007-MZ
t_ - -
---- -
------=:::::::---
• Printing paper
• Character printing
• Bit image printing
• Paging
•
Tabulation
• Feed
• Copies
• Alarm bell
--. .,
Dot Printer
MODEL .
MZ-80P5 (~AeL~
~~ 11-HS M.()D~L l'H-t: ~ AQ'"f'f([ ~~~·-HS 2.A1"LH~
e .... bH P i ~ I c 2 '2 ( w~Ut M.A.Y ~-.toT B f:. 1ltf
~Mb ~~ 1C tG, \\..1 '1l+t U,..TE.~ PS ?en .. rrf~~
~~}~:) i"-1. · ~ ~ fo f'~l)...l'Te ':;..)
---------- ------ ~
FEATURES
Can use fanfold paper 4-10 inches wide.
Four character sizes are possible.
Printing
is possible with dot units.
Number of lines printed on 1 page can be determined.
Both vertical and horizontal tabulation control is possible.
Switch for line by line paper feed and paper feed in page units.
Control is also possible through software.
Simultaneous copies, up io 3 pages in eluding the original, are possible.
Alarm bell sounds to warn the user of mechanical trouble, lack of printing
paper, etc.
• Bi - directional printing Along with bi - directional printing , there is very effective printing thanks to
the use of logical seeking. (Only 80 characters/line, 40 characters/line)
• Printing ribbon
lt can be easily put in and taken out because a special cartridge ribbon
is used.
SHARP CORPORATION

Contents
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Precautions before servicing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Explanation
of MZ-80P5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Troubleshooting
CPU board & drive PWB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Adjustment
of head driving coil energizing pulse width . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
1/0 card repair procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Power supply section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Functions
of printer parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Replacing
of main printer parts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Replacing
ink ribbon from cartridge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Repair procedure for printer mechanism . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Circuit diagram and printed wiring board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
Disasse ·mbled views . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
Packing method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
71
Replacement parts list . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72

SPECIFICATIONS
• General
Item
Specification
Printing method Impact
dot matrix
Feed methos Variable sprocket feed
Kinds
of characters 230 kinds (95 ASCII characters
+95 reverse characters
of the 95
ASCII character +40 other
characters
Character make-up 8(H) x 9(W)
dot matrix (normal
size character)
Line-to-line
space
1/6 inch or determined by pro-
gram
No.
of digits 80 digits,
40 digits, 136 digits, 68
digits or determined by software
Page
66 lines/page (line space mode)
or determined by program .
Printing
speed
80 cps (characters per second)
(ordinary
size characters)
Printing direction Si-direction
(with logical seeking)
for normal size character printing
(80 characters/line) and its double
size character printing (40 charac-
ters!l-ine). For
bit image printing
and other printing; u'ni-direction
(left to right).
• CPU Board Section
Item Specifications
CPU
Z-80A.
ROM Program TMM 2732 (4K Bytes)
Character
TMM 2732 (4K Bytes)
RAM
TMM 314APL-1 (2114L-1) (1K Bytes)
1/0
TMM 8255AC
Counter 8253AC
Other IC's 22
pes
• Power Supply Unit
Item Specifications
Input
AC 220V ±1 0% 50Hz
AC
240V ±1 0% 50Hz (for UK)
Output
DC 26V (21.5 to 26.5V)
DC
15V
DC 5V
Item
Specifications
Printing paper Fanfold paper
(4-10 inch wide)
Copies Max.
of 3 copies (including
original)
Printing paper
thickness Within 0.3mm
Ink ribbon Special cartridge ribbon
Head life
Approx. 50 million characters (14
dot character printing)
Standard interface 8 bit parallel interface (special for
Sharp personal computer
MZ-808)
Power supply
AC 220V ±1 0% 50Hz
AC
240V ±1 0% 50Hz (for UK)
Power consumption 75W
Working temperature 5
to 35°C
Storage temperatur~
-20 to 50°C
External dimensions
Approx.
377(W) X 318(D) X 105(H)mm
Weight
Approx. 6.4 kg
• Driver PWB Section
Item
Specifications
Timer IC NE555
Head driver TR
2$D986 X 9
Step
motor T R 2$D986 X 8
Others Diodes, transistors
NOTE Specifications
and appearance are subject
to change without prior notice for im-
provement. In such a
case, the explana-
tion here may be a little different from
the product.
-1-

IPRECAUTIONS BEFORE SERVICING
• The printer mechanism is fixed to the chassis with two screws to keep it from being
damaged by vibration,
etc. during transport. Remove these screws when using, main-
taining
or repairing the printer.
Fix
the mechanism again with these screws when transporting the printer.
Remove the fastening screws
• Do not apply external force to the print head, such as by touching it when it is
operating.
•
The print head becomes very hot so do not touch it with your hand until it cools
down sufficiently.
• Do
not turn the paper feeding knob (manual feed knob) when the power is on or you
will damage the paper feeding mechanism.
• Do
not print when the ink ribbon is loose.
• When servicing
and checking a printer that has been used for a long time, remove dirt,
fuzz
and dust from th~ inside, and oil the mechanism.
• There are
two types of oil, G2 and 02. Use the proper oil for each oil point. (Refer
to page 39, 40 for oi I points.)
• There are screws
and nuts which are fixed and then locked with paint for vibration-
proof etc. during transport. Paint the screws to lock them after disassembling and
replacing new parts. (Refer
to page 39, 40 for the points to be painted to lock the
screws.)
-2-

MZ-80P5 NAMES OF PARTS AND EXPLANATION OF.FUNCTI.ONS
• Names of parts
Control panel
Power switch
Appliance inlet- - ----'
Specification panel
L-------Signal terminal (1/0 POR1
L...--- - ----FG (Frame ground) term inal
Drive PWB unit - --------.
r- ----- --------- CPU board unit
Switch PWB unit
-3-

• Printer Control Flow
• Print Character Transfer Flow
• Status Check Flow
• Explanation of Signal
When the printer receives
the character code,
it raises
the signal
to a high level.
(Print character transfer routine)
(Print character transfer routine)
RDA ............ The printer outputs this signal under the following conditions. (Negative logic)
1) When the power is ON.
2) When the printer is READY.
RDP ............ Outputs from the controller to the printer. (Positive logic)
Data(RD1
,._, RD8)strobe
STATUS . . . . . . . . . Responds in the following conditions according to STATUS demands from the controller.
(Negative logic)
1) PAPER EMPTY (1 BH + 03H)
2) Printer machanical trouble (1 BH + 04H)
-4-

Clock
·
4MHz
I I
~cuit
Z-
BOA
0'1
I I
r----
Reset CPU
Circuit
IRT
...._
1
Optionla
Terminal
1\ 1\ 1\ § I I Data
Chip
Select I
~>I
8255AC
Circu1t
r--
PIO
~
()
-1111
D
f--
Control
Bus
D Add,ess Bus
Data
B!us
!
~!l
~
:2;,:e,
V
"1
.-
~
Memory
Circuit
(ROM,
RAM)
I >
Interface
Circuit
STATUS
RDA
RDP
RQ1,..._.
ROB
I I I
>I
Latch
r_
Circuit
,------->.
Head
Drive
and
Stopping
Motor
Circuit
f---
Control
SW,
Indicator
and
Buzzer
Circuit
Circuits
•
n
"
c
OJ
0
C)
~
a.
OJ
0
n
;::'
0
c.;·
c.c
~
C)
3

• Driver Board Block Diagram
Head drive
Printer
circuit
.>
mechanism
>
CPU
board
'"""!\
!\
I
Timer
circuit
*CR step
motor and
':::>
drive circuits
'>
FEED step
motor and
drive circuits
* CR Step motor= Carriage driving step motor = Timing belt motor
-6-

TROUBLESHOOTING CPU BOARD & DRIVE PWB
Push FEED SW
and
turn power
on again.
*TOF: Top of Form
+ 5V
+15V
+26V (21.5 to 26.5V)
Check power circuit.
Check printer
mechanism
FEED, TOF SW circuit
Check FEED drive circuit
Check CR step motor drive
circuit & printing head dr iv e circuit
Check printing head drive
circuit & FEED circuit
-7-
Check printer interface
circuit & 1/0 card

for
CPU board
for
DRIVE PWB
FEED, DRIVE CIRCUIT
FEED, TOF
SW CIRCUIT
YES
Check step
motor
for FEED.
Connect switch PWB.
Check FEED,
TOF switches
>----- ... and R 5, 6, 20, 19.
Check select circuit (1)
Check latch circuit
Check 023, 039, 022.
Check connecting line &
latch circuit
Check 011, 12, 13, 14 .
Check IC2
-8-
2SC 1815
2SB 743
S5277B
2SD 986
7406

Check printer head
(for DRIVE PWB check)
Check
TIMING circuit
Check latch circuit
Check IC1 and adj<;)cent
circuit
555
Check 020, 21 and adjacent I 25A 1015
':::> •I circuit 25C1815
-9-
Check 019 and adjacent 1 25C1815
circuit
Check latch circuit
Check +26V power circuit.
Check
01 to 8 250986
0 1
to
8 1
51555
010 to 17
RA 1 15953

2SC1815
2SB743
for
DRIVE PWB
7406
2SD986
74LS14
8253
for
CPU board
74LS125
Z-80A
CIRCUIT CONNECTED WITH.
CR STEP MOTOR DRIVE
Check CR step
motor.
-10 -
Check latch circuit.
Check
+26V power circuit.
Check
025, 27, 041.
~------------------~
Check connecting line and
latch
circuit
Check 015, 16, 17, 18
IC3
IC4,
03
R10, 14, 15
Check IC15, 19,
5, 17,
R17, C10.
Check select
circuit (1)
Check
IC23
2SC1815
2SB743
S52778
2SD986
7406
2SC1815
74LS14
74LS04
74LS08
74LS10
74LS74
8253

PRINTER
INTERFACE
CIRCUI"!J
(For
CPU
board check)
'
Connect cable.
Check IC1, 3
74LS125
Check
IC2
75189
Check latch circuit.
CheckiC16
I
7406
Check latch
circuit.
Check IC16 7406
Check IC11
-
11-

(For
CPU
board
check)
..._
______
_, Check
chip
select circuit.
Check IC 26
Z-80A
Check IC13
74LS02
Check IC12
74LS04
(For
CPU board check)
Check IC
11
8255
Check IC11
8255
Check reset
circuit
.
Check I
CS,
9,
10
-
12-

(For
CPW
board check)
Check oscillator circuit.
Check IC26
Check
chip
select circuit.
Check
IC26
Check IC23
I
8253
Check EP-ROM,
RAM
circuits.
(For
CPU board check)
Check oscillator circuit.
Check reset circuit.
Check R30.
Check
each
BUS line
-13-
2MHz
Z-80A
Z-80A

(For
CPU board Check)
Check
IC26
Z-80A
Check IC16
7406
Check IC27
74LS32
Check
IC26
Z-80A
Check
IC24
74LS42
Check
IC17
74LS08
(For
CPU board Check)
Check chip select
circuit
Check reset
circuit.
Check
IC26
Z-80A
Check IC11
8255
-14-

(For CPU board check)
Check
IC26
Check chip select circuit.
(IC22 : ROM 1)
(IC25: ROM 2)
(For CPU board Check)
Check
IC27
Check IC26
Check IC26
Check chip select circuit.
(IC14 : RAM 1)
(IC18: RAM 2)
-15-
Check IC26
Check IC27
Check IC26
Check IC26
Z-80A
74LS32
Z-80A
Z-80A
Z-80A
74LS32
Z- 80A
Z-80A

ADJUSTMENT OF HEAD DRIVING COIL ENERGIZING PULSE WIDTH
This concerns the printing energy force for the head wire to print a dot and its length in time as well. The shorter
the energizing pulse width (time) is, the smaller the printing energy is, thus ·weakening printed letters. To the
contrary, the larger pulse width prolongs the printing time of head wire, thereby feeding the head with the head
wire clacking out. In most cases, the head wire is caught by the ink ribbon, and what is worse, the tip of head
wire
is broken.
This adjustment is required to give an appropriate printing energy to the head wire. Make an adjustment in the
following manner.
1) Remove cabinet B. (Do not disconnect the connector of feed switch circuit.)
2) Take
out the head cord PWB connector from the connector of terminal PWB. Be careful not to damage the
head cord PWB.
3) Turn on the paper end sensor. (Put a piece of paper in the paper sensor lever located at printing paper
insertion area.)
4) Draw
out the power supply socket (N0504) with 5-pin lead from the CPU board.
5) Connect 3 units of D.C. power supply to the 5-pin connector (N0504) of CPU board as shown below:
24V D.C. (current capacity: 1.5A or more), 15V D.C. and SV D.C..
6) While pushing the line feed switch of the set, turn on the power switches of the three D.C. power supply
units. (The head is shifted right and left.)
7)
Connect the synchroscope to the collector of the transistor 019 (2SC1815) on the drive PWB to check to
see if the pulse width on the synchroscope is 400±10 J.J.sec. If the width is out of standard value, rotate the
semi-variable resistor at the drive PWB to adjust the width.
(The semi-variable resistor is to be fixed with lacquer after adjustment.)
Note: Before checking pulse width, calibrate the synchroscope to eliminate error in time base.
Synchrose ope to be
connected here
(Collector of 019)
Head driving coil energizing pulse signal
For pulse width adjustment
0 0 0 0
Drive PWB unit
CPU Board Un it
0
©
Connecting diagram for power supply and synchroscope
-16-

1/0
CARD REPAIR PROCEDURE
• Procedural
steps
(
MZ-808
MZ-80P5
trouble
Mechanical J
(
Family
check
Empty
of
paper
START
STATUS
information
Check IC1, 4,
5, 7
Check IC1,
4, 6, 7, 8, 9
Check IC2,
3,
8,9
Check IC1, 2
3, 4,
7,
8, 9
YES
(
END
)
• Checking method
of
printer interface circuit
1)
Press insulated part
of
IC
with finger
to
check
•
if
it
is
abnormally heated
......................
.
•
if
there
is
an
unappropriate change
................
.
2)
Use
a synchroscope
to
check
•
if
input
and
output
logics
of
TTL-IC
do
not
match
•
if
TTL-IC
voltages·
are
within
the
TTL
level
Note)
TTLievel:
High:
2.4Vormore
Low:
0.5V
or
less
-
17-
IC improper,
too
large load in IC, touching
between circuits
faulty
soldering, improper printed
wiring
Defective IC gate

POWER SUPPLY SECTION
• Block
Diagram
of
Power
Supply Circuit
AC 2
20V
o--
ov
AC24
(
for
UK)
Filter
Power
section
transformer
~
Rectifier
section
1--
Rectifier
section
~
....
Rectifier
section
-18-
Smoothing
Regulator
0
section section
+26V
(21
.5
""26.5V)
Smoothing
Regulator
-
<>
section section
+5V
Smoothing
Regulator
-
section
--
section
-
+15V