Service manual

REV.-A
q.6.I BOARD ASSEMBLY, C094 MAIN (Main Control Circuit Board)
Basically, the same board layout is used in both the 136-column model and the 80-column model. The CPU
on this board controls all the main functions of the printer.
It consists of a
TMP90C041F 8-bit CPU, an
E05A55YA gate array, an
E2PROM, a PSRAM, a MASK ROM, motor drivers, and head drive transistors.
PF MOTOR
DRIVER
CPU
LPAI 476H
TM
P90C041F
CENTRONICS l/F
\’ “ “
o
7
q
Cl”lp ~
E
~—
CR MOTOR
~~~f~4M ~
\\
4
~>
n
Ill
1
*PS RAM
o
0 ,,,,,
Q=
/ I +7 ”MASK ‘
OM
— — ——
T/ “ ‘
;~-
HEAD DRIVE
I
TRANSISTOR . .
CN2 for OPTION
o
0
GATE ARRAY
E05A66YA
<136-column model>
PF MOTOR
E2PROM
DRIVER
CPU
TM P90C041F
CENTRONICS l/F
pPA1476H
\// -
r
CR MOTOR
r~;--o’”
–y
qE2pR0M
g;!f;24M \
?r-
0
ml
E
,PS RAM
,(0
00
I
r ‘~ “
-
MASK ROM
0:
n:
~~
0’
CN2 for OPTION
o
0
~
HEAD DRIVE
GATE ARRAY
TRANSISTOR
E05A66YA
c80-column model>
l/F
IF
Figure 1-12. BOARD ASSEMBLY, C094 MAIN (Main Control Circuit B-d
1-29