Sharp CE-129P, Service Manual, Page: 4 / 14

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CE-l29P
7. PCU (SC6994) SIGNAL DESCRIPTION -
Pin No. Signal Name In/Out
Oescription
1 SEL2 In Select
2
SEl1
In Select
3 VOO Out
Power supply
4 ACl Notused
5
BUSY In Histl: chip select - - - - - - - - - Low: Non~lect
I
,
6
RIW
In
Hi!#l:
read Hi!#l to low transition: write
7-10 04-1 In Dm input
11
STP
Notused
12 S In
Dm
transfer mode select Une
Hi!#l: serial input - - - - - - - - low: parallel input/output
13 24
In
Print digit select Une
Hi!#l: 24 digits (GNO connected)
Low: 16 digits
14 10F Out Printer motor drive signal
15 H7 Out Printhead element on pulse
16 H6
Out
Printhead element on pulse
17 GNO In Power supply
18-22 H5-H1 Out Printhead element on pulse
23
R
In
Printer reset (printhead home position detect)
24 PD Out
Power down (in supply during printer operating cycle, otherwise,
power is not supplied to the printer drive circuit.
25 T In
Printer timing (generated from the tachogenerator of the motor)
26-28 TSl-3 In
Test pins
29 VP1 Out Printer control circuit supply power
30-32 BCl-3 ln/Out
PCU
frequency controI
33 CCK
Out Clock test pin
34
l:fA In
I
(Print density adjust pin._.JA and JB pin connection
,
Notused
I
35
HB
I
36 HC In
varies according to the printhead rank).
37,38 Cl1,2 In
Basic clock pulse control resistor fitting pin
39
PF In
Paper feed key input
40 NP In
GNO Connected
41
ACL
In All elear input
42 OP3 Out
ACl select (high when on)
43
OP2
Not used.
44 OPl Notused.
8. SERVICE CAUTIONS
I
Cautions in exchanging the printer unit
I
In order 10 prevent print density variation causecl by
thermal head resistance variation, the printhead is classified
into three ranks of A, B, and C, and the rank is indicated
on the reverse side of the printer u~it F.P .C. After exchange
of the printer unit, relevant circuit change must be observed
in accordance with the procedure mentioned below.
Leave all open when the rank B printer is used.
Short JA when the rank A printer is used.
Shrt JC when the rank C printer is used.
Table·1
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Do not sale !