Commodore 4023 a

COMMODORE

4023 1526

Technical Manual

/ S ' 2 / - V o ? 3

CONT ENT S

1 Power Supply Cir cu it 4-1
2 Rese t Circ uit 4-2
3 Cloc k O sc i l l at i o n Gen e ra t or C ir c ui t 4-3
4 CPU / Pe r ip he r y Cir c ui t D ia g ra m 4-4
4-1 Funct iona l D e sc r ip t i on 4-5
4-2 Per fo rm an ce De s cr i p t io n of El e m en t 4-6

5 Pulse W id t h C ont rol Cir cu i t 4-8

6 Motor Contr ol Cir c ui t 4-9

6-1 Paper Fe ed Moto r C ir c ui t 4-9
6-1-1 Funct iona l de s cr i p t io n .4-10
6-2 Carr iag e Mo to r Ci rc ui t 4-11
6- 2-1 Fu nct io nal D es c r ip t io n 4-11
7 Head Mag n et C ri ve C ir c ui t 4-12

7- 1 Fun cti ona l De sc r i p ti o n 4-13
8 Paper Ad va nc e S wi t ch St Ind i ca to r Ci r cu i t 4-13
8- 1 F unc tio nal De sc r i p ti o n 4-13
9 No -pa pe r Sen sor Ci rc u it 4-14

9- 1 F un cti on al De s c r ip t i o n 4-14
10 Signal C ir cu it 4-15
10- 1 Fun ct iona l De s ct i p t io n 4-16
11 Inte rfa ce Ci rc ui t 4-17
11- 1 Function al D e s cr i pt i o n 4-17

vopa p - - /sp c

P O H * ft

fc ^

1

Power Supply Circuit

J4 P4

+26 V

GNO

This c ir cu it is a sc rie s r e gu l a t or de s i g n e d to su pp ly a +5 V

(DC) po wer to the LSI, TTL, etc. inc o r p o r a t e d in the Print er
control u ni t and a +26 V (DC) po we r to the h ea d magnet,, the C A
moto r and the PF motor.

Plac in g the P O WE R sw i tc h in the O N p os it i on , the AC c ur r en t

flows thr ou gh a no ise f il t er to h a ve the lo w -r an g e line noi se

cut- ou t and is fed as the i np ut into the p ri m a r y side of the
transfo rmer . Af te r the v o l t a ge ha s be en de c r e a s ed in the

transfo rme r, it leav es the t r a n s fo r m e r to the se co n da ry side.
The AC out pu t is th en r e c t if i e d in a B r i d g e - t y p e w h ol e -w a v e

rec ti f yi ng ci rc ui t and the d i s t r i b u t e d o n a c ap aci to r. Th e

unr e g ul a te d v o lt a ge o n the +5 V side b e c om e s a p pr o xi m at e l y

9.5 V (600 mA) an d the un r eg u l a t e d vo l t a g e o n the +26 V,
app r ox im a te ly 30 V (1 A). F r o m th es e u n r e g u l a t e d powe r suppl ies ,
a c o ns ta n t +5 V out p ut is ob t a i n e d t hr o u gh the t hr ee -t er mi na l

reg ul at or (VR1) and the c o n s t a n t +26 V ou t p u t vol t ag e th ro ug h

the ci rcu it s ys te m co n s i s t i n g of Q23, Q1 9 and CR23. T he se

outpu ts are then s u pp l i e d to the va ri o u s loads.

4-1

2

Reset Circuit

74LS14

♦24 v

\|

7406

UIC .. UIC

6 3

fTE?

74LS14 74LS14

CR24

-tSH

---

-

* +•

O ^ _

M S O

OC

*
O)

ri

s i 2

R22

^Wr-

10 K

R21 ^

A/W-— r <

100

y

<N/ir

sT?i

| ri Ki

!

+5 V

> 3 <o

♦5 V

APU

— +5 V

" GNO

Whe n the pow er is tu r ne d ON, the a bov e c i r cu i t e ns ur e op era ti ona l

read in ess ( sta nd by con di ti on ) t o a l l ow ope r a t i o n a fte r r es et ti ng

the v ar iou s de v ic e s (CPU, TTL, et c.) in the de f f er e n t circuits.

Wh en the POW E R is t ur ne d OFF, it p r e v e nt s un n e c e s s a r y dot s k ip 

ping. Aft er sw i tc h in g the P O W ER ON, the +5 V s up pl y has fall en

to ap p r ox im a te l y 3 - 4 V, Q 21 e n e r gi z e s and the U1 C 5 pin
gra du al l y ris es f r om L O W to HI G H du e to the tim e con st an t of
R13C3'. Onc e the th re s h o ld of t he U 1 C is ex ce e de d , the U 1C 6 p in
goes f ro m H I GH to L O W an d b e c o m es the r e se t sig nal for the i n
divid ual devi ce s afte r p a ss i n g th r o ug h the i n ve rt er stage. Wh e n

the POW E R is tu rn ed OFF and the v ol t a g e of the +5 V s up ply

decr eas es to abo ut 4 V, Q21 swi tc h es OFF. The po wer su ppl y to the

Q20 emi tt er is c ut off, thus p r e v e n t i n g the dot pla te skip pin g

whe n the PO W E R is OFF.

Power ON •

+ 5V

Q21
co ll e ct or

U1C 5P IN

U1C 6 PI N

U1C 4 PI N

/

/

A

Appr ox.

330 m s

4-2.

200P

3

Clock Oscillation Generator Circuit

This ba sic os c il l a t i o n g e ne r at or u se s a 4 MHz cry sta l and serves

as the input to the U 10 C v ol ta g e di vi d e r after pa ss in g t hro ugh
two inverter stages. In the vo lt a ge divi de r, the U 10 C is qua rt e re d
and the 4 MHz o s c i l l a t i o n is c on v e r te d to 1 MHz, p r od u ci n g an
extr em el y stabl e cl o c k use d as the CPU clock.

The c loc k is e x t r em e l y s u sc e pt i bl e to noi se in the po wer su ppl y

and to ra di a ti o n noi s e fr om ou ts id e (etc.). It also bec om es
the sourc e od noise ra d ia t in g to the o utsid e. T he cl o ck os c il 

lation g en er at or co mp o ne n t s are th er e fo r e per f ec t ly sh iel d to
elim in ate the abo ve no is e f act or s c om pl et el y. Thus, the c l oc k
osc i ll at i on gen e ra t or is a no is e - fr e e design.

4-3

4

CPU and Per ip h er y Cir cu i r Di a g r am

4-1 Func tion al D e s cr i p t io n

(1) Data t r ns m i ss i on be t w e e n the in d iv id ua l ports and ROMs

is ach ie ved w it h an a ddr es s map. This map is i l 
lustr ate d below:

U4 D (6532 RA M AREA)

0000

X

007F

f

U 5 D( 6532 RA M AREA)

\

0100

U5 D ( 6532 I/O PORT)

U4 D ( 6532 I/O PORT) (
U6 D ( 6522 I/O PORT) ( 0 240

0300

0400

U8D( 2364 ROM. AREA)

2000

(2) The da ta is p r o ce s s e d in the c a l c u l a t i o n s ir cui t inside

the CPU.
(3) Co ntr ols the dat a flow.
(4) The input d a ta f ro m the i n te r fa ce are sto re d in the

m e mor y .

4-5

4-2 Per f or ma n ce D e s c r i pt i o n of Ele me n t

(1) U7D (6504), CPU

a. Thes e e le me n ts are 8 bi t pa rall el da ta- pr oc es s-

ing CPU and has a 8 bit d ata bus and a 12 bit ad 

dress bus and its con tr ol si gna ls are: IRQ

(in te r ru pt e d input), R / W ( re a d / wri t e output) and

$> 2 (When this si gnal bec om es HIGH, tra ns mi ss ion

takes plac e b et w e e n the CPU and the d e vic e).

b. The pr og ra m st ore d in the RO M is rea d- ou t step- by-

step and the c o r re s p o n d i n g c om ma nd s are in te r
pre te d to be p e r fo r m e d in the pr e -d e fi n ed m ac hi ne
c y cle .

(2) U4 D, U 5D (6532)

a. 128 byt e R A M and a p r og r a mm a bl e timer, plus 16

inp u t/ o ut p ut por ts are p rovid ed.

b. Wh e n r e s et t i n g (i.e., w h e n a L OW signal is fed

into the re se t term ina l) all re gi st er s have " 0”

input and all I/O buse s ope ra te in the input mode.

The y are thus pr ot e c te d a ga in st d am ag e and incor=

rect d at a l ia bl e to occu r in the exter na l parts

dur i ng i ni ti a li za t io n .

c. The CPU is ac ce s se d wh e n CS1 goes H IG H and CS2

goes LOW.

d. RS (RAM) si gna l de t er m i n ed w he a th e r the CPU

tran sm it s the d a ta wi t h RA M or w i t h the I/O.

FvS termi nal is LO W ----Data tr a ns m i ss i on w it h the RA M

RS t erm in al is HI G H Data tr an s mi s s io n w it h the I/O

e. If an s hre d f u nc t i o n is re qu es ted , in r ef ere nc e

to the CPU, a LO W IRQ signa ls the CPU that is an
sha red fu n ct i o n is req uest ed.

(3) U6D (6522)

a. This uni t has ei g ht A po rts and e ig ht B ports

wh ic h ca n be u se d as input or ou tp ut ports, de pen-

ing on the pr og ram. It also ha s bu i l t- i n pr o 

gra m ma b le time r 1 and tim er 2.

b. Acc e ss i n g wi t h the CP U is po ss i bl e wh en CS1 goes

HIGH and CS2 go es LOW.

c. Four r e gi s te r sel e c t io n term inal s RSO - RS3 are

provid ed. Thus, it of fe rs a fu nc ti on al range of
16 com b in at i on s.

d. It has two sha re d inpu t te rmin als : CA1 and CA2.

Wh e n inpu t is fed into these t er min als, the CPU

has a sh a ri ng tas k to fulfil so that the IRQ signal

is L O W to i nf or m the CPU of the s ha ri ng task.

e. Th e m a in ta s k is to ou tp ut the mo to r d riv e signals

for CA and PF.

(4) U8D (2364)

a. - 8 kb y te (64 kbit) ma s k ROM.

b. The 1 kby te at the R O Mh e a d is ”FF" w h en no da ta -

in fed in. Aft er this, the re is a p ro gr a m areas
and the sto re d area for the p r in te r cha ra ct er
pattern.

(5) U1D (7 4L S0 0)

Wi th four NA ND gates, it g en e r at e s the f oll oe in g chip

selec tor signals: U4D (6532), U 5D (6532) and U6D (6522)

(6) U8C (74LS42)

The BCD d ec imal dec oder . It g en e ra t e s the U8D (2364)
chip sel ec to r signal and the chip sel ec to r ”1" signal
U4D (6532), U5D (6522) (via the inverte r).

Out put sign al (Pin //1)

L O W

----

U 4D, U5D, U 6D s ele ct

---

HI GH

U7D (2364), RO M se le ct

4-7

5 Pulse Width Control Circuit

Cir cu it D ia gr am

♦5 V *5 v

♦ Time chan

10 mS

U6O-PB0

U

U88-Out

Q22-Collecxor

TP1

500 mS

Func tio nal D e sc r ip t i on

This cir cu it uses IC ti mer U8B (LM555) and gen e ra t e s the pow er
ON time O N time for the he a d m a g n e t of the d ot plate.
This v alu e is ad ju st e d by R 39 (20 K O h m va r ia b l e resi sto r) to

0.5 ms. Do not touch the R39.
The pul se ti ming ou t p ut is such th at w he n the pulse has b e en

input ted at the tr ig ge r ter min al it con fi r ms to the above time
char t in that the signal falls.
Wh e n the P OW E R is swi t ch 0N-0 FF , the ini tial rese t signa l is

in at the rese t t erm in al so that the re is no out p ut signal.
Simil arl y, on the ou t p ut side, the Q20 tr a ns i st or sw it ch es O N

after the Q21 tr an si s to r is ON in the ini tial rese t c ir cuit ,

and to a ll o w the TP1 sig nal to be o ut pu t, no p ul se is out p ut

for the m om e nt the P O WE R s wit ch es ON - OFF.

6 Moto r Co ntr ol Ci r cu i t

The mot o r us es a two - ph a se ex c i t a t io n sy st e m and its drive
pulses are show n in the t abl e below.

|\ Coil
1 Ste pping X

| ord er \

M0

Ml

M2

MJ

0 i

ON ON OFF OF F

1

OFF ON ON OFF
2 OFF O FF O N ON
3 ON

OFF OFF

ON j

4

ON ON OFF

OFF

NOTE: D ur in g rev er se

tran smi ssi on, the
curr en t flo w in st e p 
ped orde r th ro ug h
4, 3, 2, 1, 0.

6-1 Pap er Fee d Mo to r Ci r c ui t

Cir cu it D i a gr a m

4-9

6-1-1 Fu nct io nal De s c ri p ti o n

(1) PF h ol d signal

This si gnal is o ut pu t from PA0 of U5D (6532) and is
use d ei t he r for pape r feed or for s t op pi ng the mo tor

in the p r e- d et e r mi n e d stop po si t io n w hi l e no paper feed
takes place.

Thus, wh e n the m ot or has b e e n st opped, tr an sis to r Q17

switc hes OFF, and the p ow er pas si ng thro ug h the m ot or
coil is mad e to flo w th ro u gh a 470 O hm r es is to r (approxi.
50 mA power flow) to pr e ve n t the coil f ro m ru nn ing hot.

Wh e n p ape r fe ed takes p la ce,tra n si st o r Q17 sw itch es

ON and the pow er pa ss i ng t h ro u gh the m o to r coil is i n
cre as e d (approxi. 500 m A pow er flow) so as to p rod uc e

the ra te d torque.

PF H ol d signa l HIG H

----

Pap er f eed

L O W

------

No Pa pe r Fe ed

(2) PM0, PM 1, P M2 and PM3 Si g na ls

Thes e signa ls are ou t pu t f ro m PA4, P A5, PA6 and PA7

of the U6D (6522) and c on tr ol wh e at h e r power flows

thr ou gh the mo t o r coil pape r fe ed or not:

Signa ls PM0, PM1, PM2 and PM3

HIGH

-----

NO powe r flows thro ug h the m ot o r coil

LOW

------

Power flows th r ou g h the m o to r coil.

Irr e sp ec ti ve of wh e a th e r p a pe r fee d takes pl ace or not,
these signa ls are d e s ig n e d so that power flo ws thr oug h
eith er of the two coil s as s ho wn in the p re vi ou s table.

(3) Diodes CR17 - 20 and Zen er dio de CR21 use d in this

cir cu it pre ve n t d am ag e to co il driv e tr an si sto rs Q13

- 16 re s ul t in g fr om the co u nt e r - el e c t r o m o t iv e force

gen e ra t ed w he n the pa ss ag e of the cur r en t thr ou gh the

coil is terminate d.

Surv ey figure:
Tr a ns i s t or / Co l le c to r Vo l ta ge W a v e f o r m

* W it h no CR17 - 21

force

6-2 Car ri ag e M ot o r Ci rc ui t

Cir cu it D i a gr a m

6-2-1 F un ct io na l De sc r ip t i o n

(1) CA Hol d Sig nal

This si gna l o ut pu t fr om PA1 of U5D (6532) is use d
eit her to m ov e the c a r r ia g e or to stop the m ot o r

in a p r e- d et e r mi n e d p o s i t i o n w i t h o u t mo vi n g the
carria ge. The ci rc ui t f u nc t i o n is i dent ica l to that
of the PF HOLD sig nal (e x pl a i ne d on the p re vio us
p a ge).

(2) HM0, HM1, HM2 and HM3 s ig n al s

The se sign al o ut pu ts o r i g i n a t e f ro m PM 0^ PM1, PM2

and PM3 of U6D (6522). Th e op e r a t i o n o f't he cir cu it

is i de nti ca l to that w i t h the PM0, PMl, PM2, and

PM3 s ig na ls (exp la in ed o n the pre vi ou s page).

(3) As al so de sc r i be d on the pr ev i ou s page, CR13 - 16

and C R2 2 suppr ess the co u n t e r - e le c t r o m ot i v e v ol t ag e

to m a i n t a i n it at ap p r o x i m a t e l y 50 V to prot ec t
the tran sis tor .

4-H

7

Hea d Mag ne t Driv e Ci rc ui t

Cir cu it Di a gr a m

pi ji

Time Chart .

PBO - PB7

Ql - Q8 bas e

Ql - Q8 c ol le cto rs

Approx. 1.5 ms

As this is an o p en c ol le c t or circuit,

500 us

the TP1 out pu t g oes HI GH on ly w he n pull ed

up and goe s L OW afte r this.

4-12.

"s.

Co u n t e r- e l e c tr o m o ti v e v olt ag e
approx. 50 V

26 V

1

Fun ct io na l De s c ri p t i on
This c ir cu i t is de s ig n e d to dr iv e the m a g n e t o pe ra ti ng

the cha r ac te r g e n er a t i n g plate.

(1) Th e out pu ts PB0 - PB7 fr om U5D (6532) go LOW in

approx. 1.5 ms.

(2) T hes e outp ut s be c om e s H I G H by pa s si n g t hr oug h an

ope n co ll ec t or and in ve r te r sin ce this is o nly for

the mo m en t the col l e c to r side is b e i n g p ulle d up
whi le p as si n g t h ro u gh the re si s to r (i.e., con ne ct e d
wi th TP1), the d u r a t i o n of the H I GH c on d it i o n is
only 0.5 ms.

(3) Thi s HI GH si gn al cau se s tran s is t or s Q1 - Q 8 to

swi tc h on.
The Zener di od e and d io de s of CR1 - CR1 2 p rot ect

tra ns is to rs Q1 - Q8 from be i n g d a m a g e d by the c o u n t e r 
el e c tr o m o ti v e v o lt a g e ge n e r a te d w h e n the m ag ne t

is bei n g t ur ne d OFF.

Paper Ad va nc e Swi t c h and I n di c a to r Ci r cu i t

Cir cu i t D ia g ra m

+s v

US D

(6532)

PA 3

£ R 54

P3

J3

PF K ty

0 ^ 0

11

> 4 7 0 n

i

U 2 0

1

1

PA 5

11

____________

J X

_______

ho

1 2

J

j

Pr-

±

1 Fun ct ion al De s c r i p t io n

(1) Wh e n po wer is tu rn ed O N and the pr o g r a mm opera ti ona l,

PA5.i s h el d L O W an d be c om e s H I G H after pa ss in g thr ou gh
U2D (i nve rte r), cau s in g the ind i ca t or to light.
Howe ve r, if the pr in t er run s out of paper while
pri n ti n g is in pro gr es s, .the i n di c at o r flashes.

(2) D ep r es s in g the pape r adva n ce sw it c h allow s the U5 D

(6532) to det e c t that PA3 has a L O W input and IRQ

is ma de to go LO W in the CPU, le ad i ng to the i n te r 
rupt pr o g r am b e i ng exe cu te d. As a result, paper
feed is e nab led . How ev er , w h i le pr i nt i n g is in
prog res s, the In t e rr u pt si gnal is ignored.

4H3

9 No- Pa pe r S en s or C ir c ui t

Cir cu i t Di a g r am

+5V

9-1 Fu nc t io na l D e s cr i p t io n

Op er a t i ng this s w it ch is a ll o ws the U SD (6532) to d et ec t

that PA2 has gon e to L O W i np ut and IRQ is m a d e to go
LO W in the CPU, l ea di n g to the in t er r up t p r o gr a m b ei n g
exec ute d. As a re sult, p r i nt i n g is sto pped. W i t h the

start of a n e w line, the C P U ch ec ks this si gnal in it ia l ly

so th at p ri n ti n g is not a r r es t e d m i d - l i n e (i.e., w hi le

a line is b ei n g printe d).

4-14-

10

Signal C ir cu i t

Cir cui t Di a gr a m

♦sv

Time Char t
* T i mi ng Signal

UlC -9? in

IM IM /U lf

UlC -8 P in

(PA6)

— il— Approx. 1.5 ms

uuuuimr: : : :

. P lat e m a gn e t c ur r e nt
\ f l ow op en i ng po s it i on

* Rese t signal

U1C-11 pin

'Ji

Plate mag ne t
curr en t flow
ope ni ng po si tio n
for the next
l i n e .

__________

r \

U1C-1 0 pin

(PA7)

Wh e n ca rr i a g e has /r-

re tu r n e d to its

hom e p os i t i o n

(Print s to p signal)

\

Pri nt start

signal for next

line print

4-IB

10-1 Functional Description

Whe n the pr int er c arr ia ge s ta rt s to move, the timing

signal is re le a se d from the pho to tra nsis tor. W he n the
carr ia ge arrive s to its hom e posi ti on , the rest signal
goes HI GH (CIU - pin 10) and the n ext timi ng signal

(UIC - pin 8) rises, op en i ng the cu r r en t flo w to the
dot plate magn et.

4--IÉ

11

Inter face Ci rc u le

Cir cu it Dia g ra m

♦■5V

11-1 Fu nc tio na l De s c r i p ti o n

(1) The DIN 6- pi n co nn e c t or has the f ol lo w in g pin

arra nge ment :

Pin 1 SR Q (Se rvi ce Req u es t)
Pin 2 G N D (Sign al G rou n d)
Pin 3 AT TN (At ten ti on)
Pin 4 CL K (Clock)
Pin 5 D AT A (Me ss age s an d data)
Pin 6 R ST (Reset)

Frame FG (Frame G rou nd )

(2) D e s cr i p ti o n of Si g na l s

a. SRQ is a si gna l us e d w i t h the ha rd w ar e. It is pull ed

up to 5V by pa s si n g t h r o u gh a 1 k O h m res is ta n ce

on the p ri n t er side.

b. GND is the S IG N A L G R O U N D S i g n a l d es i g n e d to un i fy the

signal le vels of all co n n e c t e d e q ui p m e n t ( inte nded

for the in s t a ll a t i on of a h os t c o m p ut e r later).

c. Th e AT TN sig nal is to inf o r m the pr in te r that the

/ £ ~ 2 é -

CON TE N TS

Ma in t en a n c e

Tro ub l e sh oo t i ng

1. Mai n te n an ce
(1) To r epa ir p r in t er ma l f u n ct i o n s co r r e ct l y and eff ic ie nt ly ,

it i s - im po r ta nt to d i sc ov e r the caus e( s ) of s uc h m a lfunc

tion clearly. For this p urp os e, it is ess e nt ia l that the

mai n te n an c e pe rs on ne l for this pr i nt e r sho ul d ha ve a

perf ec t un d e r s t a n d i ng of ho w the pr i nt e r wor ks a nd be
tho ro ug hl y fam i li ar w i t h the p r o c ed u r e s for pri n te r
dis ass em bly , assembl y, ad ju s tm e nt and lubr ic at ion .

(2) W h e n h a nd l in g the m a ny in te gr a te d c ir c u i t b oa rd s (MOS

ICs) suc h as the pr i nt e d ci rc ui t bo ar ds , it is nec e ss a ry
to eli mi na te the s tat ic e l e ct r i c it y bu i l d - u p on the bo dy
as ot he rw is e the el e ct ro n ic c o mp o ne n t s m a y be da mage d.

(3) T urn OFF the pow er sup pl y be f or e ex e c u ti n g any m ai n t en a n c e

and/or r e pai r tasks.

(A) Af ter f in i sh i n g the m a in t e n a n c e a nd/ or r epa ir ta sks be

sure to c he c k if thes e h av e b e en p ro p e r ly com ple te d.

(5) P r in t ed cir cu i t b oa rd s m u st be co v e re d wi t h co n du c t iv e

sheet ing d ur in g tr a n s po r t a ti o n or storag e.

(6) Bef ore t es t - st a r ti n g the p ri nt e r to co nf i r m that the

mai n t en a nc e a nd/ or rep ai r ta sks ha ve b e e n ca rr i ed out

prop er ly it is e ss en ti al to ch e ck that th ere

for eig n m a t t er s inside the p ri nte r.
(7) Be sure alw ays to us e onl y the s pe c if i e d r i b b o n ca rtrid ge.
(8) Be careful and re m em be r tha t c o nd e n s a t i o n m ay l ead to

short circuiting..

(9) W h e n c o nn e ct i n g the pr in te r to the pow e r supp ly, chec k

that the pow er a va il ab l e me et s the v o l ta g e re qu ir em en t.

(10) Use only sc r ew dri ver s that fit pr o pe r l y in the gro ov e

of the sc re w head.

_

e no

6-1

1. Though the

does not

in i ti a l i ze .

has been

the pri nter

POWER switc h

turned ON,

SYMPTOM S

2. fR OUB LE SHOOTING

5) Other items

6-2

. Power cut

. Devi atio n from the re

quired AC input vo ltag e

*

4) Main PCB unit

. PCB is sho rt -ci rc uit in g

or its compon ents are

shor ^ c i r c u i t i n g .

defect ive

3) Power supply unit

. Power supply unit is

. No contact betw een

connector P4 and J4

2) Fuse(s)

. Blown fuse(s)

. The power supply cord is

. The power supply cable is

broken.

de f e c t i v e .

1). Power cord

'. Power s upply con nec ti on

defect ive

to the terminal is

ITEMS TO BE CHEC KED

POSSIB LE CAUSES

: connect the power cord at

. Use a teser to chec k and

te r mi n a l .

the specified out put

Y R epl ace /r epa ir mai n PCB.

. Replac e/r ep air the power

. Connect the con nec tor

supply unit.

main PCB unit and the

other relevant items.)

fuse it blows again, check

the power, supply unit, the

. Replace with the specified

fu s e (s ) .

(If after r epl acing the

. R epl ace /r epa ir the power

cord.

. Replace /r epa ir the

. Check the co nn ect io n to

power t rans mis sion cable.

the terminal again.

REMED Y (REPAIR MEASURE)

2. Does not

print

SYMPTOMS

6) Printer . No conta ct betwe en

5) Host comp ute r

4) Ribbon car trid ge

3) Paper advance

lamp flashes

2) Paper advance

lamp OFF

1) Paper advance

lamp ON

ITEMS TO BE C HEC KE D

6-3

. Main PCB def ective

connect or PI and Jl.

. Computer m is fu nc ti o ni ng

. Interface conn ect ion

defect ive

. R ibbon ca rtrid ge has run

. No ribbon cartridge has

empty.

been installed.

. Paper has not been

. Paper runs out while

properly inserted inside

the printer.

printi ng is in progress.

. No contact betw een

connector P3 and J3

. Paper has not b een pr o 

perly inserted.

POSSIBLE CAUSES

. Repl ace /re pair PCB.

. Connect connector.

. Re-conne ct interface.

. R ep rog ram comput er

. Replace the ribbon

. Install a new ribb on

ca r t r i dg e .

ca r tr i d g e .

switch.

correctly. After this,

press the PA PER ADVAN CE

. Repleni sh paper.

. Turn the m anual knob

and set the paper

properly.

. Connect the con necto r

. Insert the paper

REMEDY (REPAIR MEASURE)

5. Recor din g paper

not co rrec t

(Fan-Fold paper)

feeding pitch

4. No recordin g

fe d .

paper is being

position

3. Docs mi ss ing in

character c o m 

the pr int ed- out

SYMPTOMS

3) Release lever

2) Paper h ol d-d ow n

1) Tractor

1) Pla ten

3) Print head

2) Head shift lever

1) Ribbon c artri dge

ITEMS TO BE CHE CKED

6-4

. Release lever set b ackward

arrow.

in the d ire ct ion of the

. Paper hold -do wn comes up.

. Tractor pins and paper

perfo rat ion are mis 

aligned .

. Main PCB defective.

. Paper feed mot or not

rotating

. FPC br oken

. Head (over 30 m ill ion

. Main PCB d efec tive

. Lead terminal of the

ch a r a c te r s )

connec tor Jl defective.

, Head shift lever pos itio n

. Ribb on life (Over 600,000

ch a ra c t e r s )

POSSIBLE CAUSES

. Adjust the release

of the arrow.

lever in the d ir ec ti on

. Set the paper hold -d own

. R e-set the paper to

align.

. Repla ce/r epa ir ma in

. Repair con nec tor Jl

. Re-conne ct conn ector

PCB.

PI and Jl.

ter m i na l .

. Replace head.

. Replace head.

. Replace /r epa ir PCB.

. Repair c onn ecto r/te rmina l

. Re-set the shift lever.

. Replace ribbon cartrid ge

REMEDY (REPAIR MEASURE)

6. Print head not

properl y

func tion ing

(Letter paper) 4) Tractor

SYMPTOMS

1) Print head

5) Release lever

ITEMS TO BE C HEC KED

6-5

. Print head stopped

arbitr ari ly

. Release lever set in

arrow.

the dir ect ion of the

. Tractor po sition . Align the tractor with

POSSIBLE CAUSES

. Turn POWER sw itch from

OFF to ON to in itialize

the printer.

. Set the releas e lever

opposite to the d i 

rection of the arrow.

the width of the paper.

REMEDY (REPAIR MEASURE)

U

U5D-65 32(P rin t he ad control)

U6D-6522 (Mot or control)

CN No. PI

28P

Printer m ec han ical unit

(Main PCB unit)

CPU: U70 0ÜO4

ROM: USO 2364

114 D-6 5 32 U50-6532

(Interface control)

CN No. P6

4P

CN No. P7

6P

CN No P3

3P

CN No. J3

3P

(Switch PCB unit)

6-6

é

t

ü

Power advance SW.

CN No. P4

4P

(Power supp ly unit)

Print head

TI Feed motor

^

(notor

---------

Carriage

CH AP TE R 7

Ma l fu n c t i o n and R e p a i r

(CB M- 1526)-

CO N TE N T S

1. App l i ca t io n 7-1

2. Ide n t if i ca t io n and nom e n cl a t u re of the par ts 7-1

3. R ep a ir p r oc e du r e s 7-2

4. Ty pe s of m a l f u nc ti on 7-2

5. Re a ir 7-3

1. Ap p l i c a t i o n
Th is c h ap te r d is c ri b es the ma l f un c t i o n a nd re pa ir in

re fe r en c e to the s erial d ot pr in te r C BM 1526.

2. I d e n t i f i c a t io n and n o m en c l a t u r e of the par ts.

The par ts are d ev i de d in to su b di v is i o ns a c co r di n g to

fu n c t io n as sho wn b elow .

Fig. 1.1 B lo c k Di a gr a m

■» -

3. R epa ir P ro c ed u r e s
3-1 C hec k for r e p e a ti t i o n of m a l f un c t on

If r e p e ti t io n of m a lf u n c t i o n d oes not o ccur ch e c k
the input pow er supply, t em p e ra t u re s no ise , s hock, etc.

as the c aus e . '
3-2 Vi su a ll y ch ec k to see if ther e are any h an d l i ng errors.
3-3 If ther e is a ha n d li n g e rr o r in e ne of the areas repai r

only the ar ea involved. Che c k the fu n c ti o n of the inv olved
area.

3-4 If th ere is no ha n dl i ng e rr o r found. Che c k the fo ll ow in g

usi ng a s yn c ro s co p e or vol t a ge mete r: input v olt ag e, AC

outpu t vo lt ag e , DC vol t ag e (+5V, +26 V), pu ls e w i d t h to
the h ead m a gn e t, etc.

3-3 Re pl a c e me n t of m a l f u n c t i o n in g po r t i on or b l o ck up o n

an a ly sis .

3-6 Check to see if the rep ai r ed p or t i on is fu n c ti o ni n g

pr o pe rly .

4. Types o.f M a l f u n c t i o n
No me n cl a tu r e and sy mpto ms of the types of m a l f un c t i on as

shown belo w.

TYPE OF MA L F U N C TI O N

SYM PT O MS

Dot m i ss i n g

Dot to be p ri n te d is mis si ng .

C

o

Wr o n g p ri nt

Wr o n g l et te r pr inted .

CO

1-1

>

Abn o rm a l pri nt

Mi s p ri n t or a bnor mal let te r printed.

Q

Fain t p ri n t

Fain t print.

u

C

1-1

M

Ri b b o n feed

Abn or m al rib b o n feed.

Pu

Ri b b o n s e tt i ng

Can no t set the r ib b o n (properly)

C

o

No pap e r feed

Does no t feed the pap er at all.

1-1

CO

Ina d eq u a te p ape r

.Paper feed me c h a n i s m ina de qu at e to

>

feed

amou nt r e q ui r e d

Q

Abn o rm a l pap er

Fac to r s r e la te d to pap er feed

Feed

feed

me c h a n i s m ot he r than the above
m e nt i on e d.

U

0)

He av y k no b

Up o n t ur ni n g on the sw it c h the

Ou

kn ob is ex tr e m e ly he a v y

o*

No pa pe r detects,

tion

Pri n ts w i t ho u t p ap er

7-2.

Other Divisions

No op e ra t i o n

Does not op er a t e wi t h the s wi tc h
tur ne d on.

No p ri nt sta rts

Op er a te s w i th the sw it ch tu rne d on
but doe s ho t pri n t the d ata fr om

the h o st c o m pu t e r '

Speed too s low

The m o v e m e n t of the pri n t h e ad is

too slow.

Left and r igh t

speed

The s pp ed of the p ri nt hea d from
the left and ri g ht diff er s
c o n siderably.

He av y he a d

Up on tu r n in g on the s wi tc h the
movement' of the pr in t h ea d is

ex t r em e l y heav y.

Irr eg ul ar stops

Stops wh i l e pr i n t i n g

Lam p lig hts

Up on t u r n in g on the sw itc h the lamp

does not li g ht up lamp does n ot
fl as h e v e n w i t h o ut pape r

Prin t he a d

ov er h e at i ng

Smo ke ris es fro m the p rint he ad

Abnor ma l s ou nd

Abn o rm a l soun d is h e ar d

Ap pe a ra n c e

Scr at c he s, acc u m ul a t i o n of dust,
dint, etc.

Parts m i s s i n g

Ne c e s sa r y par ts m i s s in g

5. R ep air
Items to be ch eck ed , c aus as and r e me d y in r es pe c t to

the p ar t ic ul a r type of m a l f u n c ti o n are d e sc r ib e d
as follows.

7-3

ITEMS TO BE !

CHE CK ED

CAU S E

RE M E D Y

Che ck w av e fo rm of

tran si sto r col l ec to r

and b as e (note in

Pre m at u re w e ar of
prin t head .

Shi ft h e ad posi t io n '

tow ar d the pla te n

wi t h the shi ft lever.
par ti cul ar the vo l t
age and the pulse.

Che ck the re si sa nc e
value of the hea d

tnagne £.

The p r in t h e ad

rea ch e d the end

of life.

Re p l a c e the head.

Check that no lines

j

are broken.

j

1

The r i b b o n ha s
rea ch e d the end

of life.

Re p l a c e the rib bon

c a rtridg e .

The AC v o l ta g e

input does no t
con f i rm w i t h re 
qu ir em e nt

Use the pr op e r
vo lt a g e

indicated.

ci
£

CO
CO

T -l

B

-0)

-U
O

-

The F PC of the
prin t h ea d is
broken. (Make

sure the FP C do es

not hit the rib-

Ibon car tr i dg e. )
1

Re p l a c e the head.

O

FPC c ab le of the

me c ha n ic a l pa rt

broken.

Re p l a c e the m e c h a

nica l part.

Line b r o k e n in
me c ha n ic a l part.

R e -c o nn ect .

The p ul se w i d t h

app lie d d if f er s
from the setti ng.

Re- a dj u s t. (If set

too long, it may

re s u lt in the h ead
ove r he at i ng .

¡Drive tr a ns i s t or
¡on the c on tr o l

¡PCB de fe ct iv e.

Re p l a c e transi stor.

1

¡Control P C B (LSI,

•etc.) de fe ct i ve .

I
Re pl a c e LSI, PCB,
j etc.

7-4

ITEMS TO BE

CHE C KE D

CAUS E REM E DY

PRINT WR O NG / AB N OR MA L PRINT

Ch ec k that no
eq u i p m en t | m a c h i n e ry

is be in g us ed whi c h

Nois e f ro m e x ter
nal mach i ne ry |

equipment.

Avo id e u si n g the printe r

in a spa ce l iab le to '

n o is e.

cre ate s in te r fe r e nc e

(n o i s e) .

Int er f ac e c ab le
defective.

Re pa i r or r e pl ac e

int er fa ce cable.
Che c k there is
no th i n g w ro n g w i t h

Hos t c om pu te r

ma lf u nc t io n in g .

Rep a i r host computer .

L.L1C illLClidLC Ld Ul C »'

Che ck that the ho s t
com pu t er it self does
not

The AC v o l ta g e

input does not
con fi r m wi t h -t h e

r e q uireme nt.

Use the p r o
per vo lt ag e

in d ic ate d.

maii un cL io n.

Ri b b o n w a s te etc.

adhering.

Cle an aro und the rib bo n
guide insi de the prin ter
bod y

Contr ol P CB (LSI
etc.) def ec tiv e.

Re pl a c e LSI, PCB, etc.

FAINT PRINT

Re mo v e the ri bb o n

car tr id ge and ch e ck

ho w the c ar bo n on

the r i b bo n has b e e n

The ri bb on cart
ridg e has come
to the end of

life.

Re pl ac e the ri bb on
cart ridge.

u s ed -up .

The pr in t h e ad
has come t o the

end of life.

Re pl a c e the head.

Shift the h e a d p o si t io n

tow ard the pl at e n wi th
the lever.

RIBBO N FEED

Che ck if the r i b b o n
has b ee n pr o pe r l y

set.

Ri b b o n is lo os e

or has com e to

the end of life.

Cor re ct r i bb o n s ett in g
or r ep l ac e r ib bo n

cartri dge.

Ri b b o n is

imp ro p er ly set.

Set ri bb o n corr ectly .

Ri b b o n feed g ear

defective.

Re pl a c e gear.

No gre ase on ge ar Lub r i ca t e .

Ri b b on f e ed - i n is

d e f ective .

Cor re ct r i bb o n or
rep la ce r i b bo n ca rt r id g

.

ITEMS TO BE

CHE C KE D

CAU SE

RE M E D Y

O
Z

HH

H

Che c k for a b n o rm a l i 
ties arou nd the r ib
bo n guide.

Hea d has come the

end of life.

Re p l a c e head.

t

H
LJ
LO

Ri b b on g uid e de

for med .

Re p a i r head.

O
QC

CQ

HH

DÉ

Dirt or r i b bo n

was te a d h er i ng to

the r ib b o n guide .

Clean.

Che ck for wa v e fo r m

of pins 25, 26, 27

Drive tr an s is t or

defect ive.

Re p l a c e tran sisto r.

ailLi ¿O Ui Ji. •
Che ck w av e f o rm at

Lead broken.

R ep ai r.

O
u:
U

DI

U

col le ct or and ba se

of Q 13.14 , 15, 16

and 17.

PF mo t or defectiv«

■. Aft er asc e rt a in in g
the cause, re pl ace
the m ot o r or the

me ch a n ic a l unit.

<

r>

O

Fo re ig n m a t t e r on
the gear.

R em ove.

¿1

PCB (LSI, etc.)

defe ctive.

Re p l a c e PCB /LS I, etc.

1

CD

< O

b3

CS LJ

Chec k w a v e f o rm at
pins 25, 26, 27 and

28 of Jl.

Pape r rel e as e

lever setting.

Cha n g e over to the
op po s it e side in the
di r e c t i o n of the arrow
us i n g the norm al paper.

INADEQU ATE 0

NORMAL PAPER F

Pape r ot he r t ha n

spe ci fi ed is beinj

u se d.

Use sp ec if i ed paper.

r

>

Wr o n g se t ti n g of

the pape r h ol d
dow n ro ll er and
the paper.

C o rr ect .

Ch ec k sw it ch in g

wa v e fo r m at pin 14

of Jl.

Q7 defe cti ve .

Af te r a sc e rt a in i ng

the cause , re pl ac e Q7.

KNOB

Fo re i gn ma t te r s
on the gear.

R em ov e.

HEAVY

PCB (LSI, etc.)
defe ctive.

Re p l a c e LS I/P CB , etc.

7-6

ITEMS TO BE

CH E CKED

CAU SE REM E D Y

Che ck w av ef o r m at

pin 18 of J1 wh il e

Mic r o swit ch

lever d e f or m e d

Re pl a c e m i c r o switch.

HO PAPER

DEFECTIOÎ

iilowl tlUg pdpaci •

Mic r o swi tc h

d e fective.

Re p l a c e m i c r o switch.

PCB/L SI etc.
defective.

Re p l a c e PCB /L S I etc.

Chec k 26 V DC and

5 V.

Blow n fuse.

Aft er c h ec k in g the

cause, re pl a ce fuse.

2

AC input v o lt a g e
does no t

con fi r m wi t h the

requ ire ment .

Use the pr op e r

vo lt ag e indic ate d.

o
*—1

H

c

C£
LxJ
CL,

AC cable ciscor.--
nec t ed or

d e f ective .

Re p a ir or r ep la ce .

C
o

2

Con ne c to r etc.
d i s connec ted.

Correct .

PCB /LS I etc.

defective.

Re p l a c e PC B /L S I etc.

Che ck pa per or
paper setting.

No pa pe r or

paper s et ti ng

inco rre ct .

C o rrect.

CO
H

<
H

m

H
2
HH

0É
CL,

Int er fa ce c ab le

imp ro p er ly c on
nec t ed or d e fec
tive .

Rep a i r or r ep l ac e

int er fa ce cable.

No da ta tr a n s

mi s s i o n fr om the

hos t comp ute r.

Ch ec k hos t c om p ut e r
conn ec tio n.

o
2

PCB /LS I etc.
d e f ective .

Re pl a ce LS I /P C B etc.

O

m

H

X O

Che ck if pT in t he ad

func ti ons cer re ct-
ly w it h the powe r
supply swit che d OFF

Ri bb o n has com e

to the end of
life or is w o u n d

• in.

Rep a ir or repl ac e

rib b o n ca rtri dge .

HH
C£

i Q
HbJ
Cl, Lx]
U3CL,
.-3 CO

Che ck the 26 V DC
supply.

PCB /L SI etc.

d e f ective .

Re pl a c e LS I / P C B etc.

7-7

ITEMS TO 6E----------

CHE C KE D

CA US E

RE M E D Y

T-s ig na l impro pe r

ly adjust ed.

C orr e ct .

«

HEAVY HEA D

Che ck swi t ch in g
wa v e f o r m at pin 21

T1 ..

Fo re i g n m at t er s

on gear.

R emove.

Ui J i

•
Q 17 de fec tive .

Aft e r e s ta b li s hi n g

the cause, re pl ac e it.
(Al l ow i ng the c urr en t
to fl ow leads to

dam a ge of the CR motor .

IRREGULAR STOPS

Che ck w av e f o rm at

R u n out of paper. Inser t new paper.

pxii J. O VJX WililC

in se rt i ng paper.

•licro s wi tch

lever d ef or m ed or
imp r op e r ly adju ste

Re p l ac e or re-a dj ust .

d.

No n -s p e c if i e d

pap er is be in g
u sed.

Use the s pe cif ie d

paper. It is not p er
mi s s i b le to use paper
with a t hic kn ess less

th an 0.05 mm.

Noi se from exter
nal e qu ip m e nt or
m ach i ne ry.

Av o i d u si n g the pr in te r

in a lo ca ti on subj ec t
to in te r fe r en c e (noise).

Int er f ac e cable

disconnected.

Corr ect .

PCB (LSI etc.)

d e fective.

Re p l a c e PCB, LSI etc.

LAMP LIGHTS

Che ck the co n ne ct i on
be t w e e n P3 and J3.

P3 and J3 no t

co nn e c te d pro pe r
ly.

Corr ect .

Pap er adv an ce

swi t ch de fe ct iv e.

Re p l a c e pap er ad va nce

switch.

PCB (LSI etc.)

d e fectiv e .

Re p l a c e PC B (LSI etc.).

ITEMS T O BE
CHE CK ED

CAU S E RE M E D Y

Chec k Che AC input
volta ge, the 26 V DC

curren t, and the
pulse wi d t h pa ss i n g

i nfn f Vie Vie aH Tnaanef..

AC input v olt ag e
does not con f ir m

wi t h the v o lt a ge

r e q uire ment.

Use the pr ope r

vo l ta g e

indic at ed.

lllLU LllC UCflU UlflgUC U‘

(0.5 m s ).
Check the res is t an c e
of the F G -a n d- m ag ne t

commo n system.

Pul se w i d t h
pa s s in g into the
hea d m a g n e t does
not c on f i r m w i th

the re qu ir em en t.

Re -a d j us t . (Adjust the

vo l um e wh i le loo king
at the sy n c r osc op e.)

o

z

Am bi en t t e m p e r a 

ture too high.

Tr a n s f e r to other

l o cat i o n.

♦—1

H
<
u

5

Ex c es s i v e l y hig h
pr in t duty.

Be ab so l u t el y sure not
to p r i nt in exces s of
the ra t ed pri nt duty.

>
o

o

<

Lx]

FG or SG short-

ci r c ui t i n g in the

powe r ci rc ui t to

the he ad magnet.

If the re is some
fo r e ig n m at ter s, rem ov e
i t.

PCB (LSI etc.)
d e fect i ve.

Re p l a c e PCB (LSI etc.).

Hea d m ag n e t short

ci rc u i ti n g or in
ope n ci rc ui t due
to the abov e
reason .

Re p l a c e head.

Turn the m an ual
knob w i t h the pow er

supply swi tc he d OF F
to c he ck it doe s not
stick.
Check wa v e f or m
at Q9 - 18.

■Foreign ma t te r s
on gear.

R em ov e.

Gea r d efe cti ve.

Re p l a c e gear.

O
z
z
o

in

Wr o n g a d ju st me nt

of powe r p as si n g

to the hea d ma g ne

Re- a dj u st m en t .

c.

.J
<
z
c*
c

Tra n si s to r /

cap a ci t or noise.

Re p l a c e tr ans ist or /

c a pacitor.

z
CQ

<

PCB (LSI etc.)
defective.

Re p l a c e L S I, P C B etc.

lx]
O
z
<

0É
<
IXJ

Chec k if a ny th in g
ext re m el y se riou s
has occ urred .

Scratches. If co n si d e r ed u n s a t i s 

fact or y, re pl a ce case,

etc.

ITEMS TO BE

CHE C KE D

CAU SE

Dirt. Clean.

RE M E D Y

Chec k that p arts
falle n inside the
un lu •

PARTS MISSING

No a cc e ss or i es ,
etc.

Some p art s ha v e
fal le n in si d e the
pri nt er u ni t or

insid e the packagi

Rep le ni s h.

Ch e c k w h y these parts
hav e d r op p ed off and
r e pa ir.

n-io

JUSTERINGSPROCEDURE FOR U 022P

9e>23 A//>$ 9oZ

Forst fjemes kabinetoverdelen ved at losne 4 stk. stjerneakruer 1 hunden

l.

af printeren.

2.

Dernsst indtastes f0lgende program:

10 0PEN 4 , 4

20 PRINT #4,"I "¿ SPC C 78 >"I"
30 G 0 T 0 2 0

Forblnd oscilloskopprobe til ben 8 pâ U1B og oscilloskopet

3-

f0lgende mâde:

2V/DIV DC o,2 mS/DIV negativ trig

H.

Papir issttes printeren, og der skrives RUN.

Folgende grafer fremkommer pâ oscelloskopet:

F0r justering:

Efter justering:

fe -ute) </°2? f /iss

forkert

” den ene printretning

J

den anden printretning

korrekt

r ~

den ene printretning

den anden printretning

indstilles

fût

pâ

Justeringen foretages ved at forskyde den lille sensor-printplade, der er
monteret pâ siden af stepperootoren. Steppermotoren er placeret i hojre

aide af printeren og sorger for, at skrivehovedet bevages fra side til ai

de hen over papiret.

5. Efter justering testes printeren ved at k0re en udlistning af et stort

program.

This was brought to you

from the archives of

http://retro-commodore.eu