Service manual

5) Dot solenoid drive circuit
The DOT1 ∼ DOT4 (the dot solenoid drive signals from the MPCA6)
are pulled up by the VRESE and converted into LOW by the driver IC.
A +24V voltage is applied to the solenoid. This operates the dot wire.
6) Paper feed circuit
The PFJ0 (the journal paper fed signal from the MPCA6) and the
PFR0 (the receipt paper feed signal) are pulled up by the VRESE and
converted into LOW level. A +24V voltage is applied to the solenoid.
This operates the paper feed solenoid.
7) Stamp circuit
The STAMP0 (the stamp solenoid drive signal from the MPCA6) flows
through the driver IC to the solenoid. A +24V voltage is applied to the
solenoid. This operates the stamp.
8) Caution
CAUTION
If fuse F2 should be blown, the dot head solenoid may be shorted. Be
sure to check the head impedance and driver breakdown.
When fuse F2 is blown:
1 Remove F2, and perform the service resetting. The set the mode
switch to a position other than SRV and SRV’ and turn off the
power.
2 Install fuse F2 (1.5A) and turn on the power.
If the fuse blows with the above operation, driver STA401A may
be shorted.
3 Turn off the power.
4 Disconnect the printer cable from the printer. Measure impedance
between the printer body connector pin 5 and the following pins:
1, 3, 9, 11, 13, 21, 25
The impdenace must be 10.5Ω ± 10%.
If impedance is outside the above range, the dot solenoid is bad.
Replace the dot head unit.
VRESC
R53
R52
Q6
RA9
DOT1
~DOT4
IC8
DOT1~DOT4
RA9
IC9
DOT5~DOT7
DOT5
~DOT7
MPCA6
+5V +24V
VRESC
R53
R52
Q6
RA9
PFJ0
PFJ0
R56
PFR0
MPCA6
+5V
+24V
PFR0
Q7
F2
IC9
IC10
STAMP0
STAMP
MPCA6
+24V
F2
IC10
VCOM5
VCOM7
VCOM17
VCOM23
DOT31
3
9
11
13
21
25
DOT7
DOT5
DOT2
DOT1
DOT4
DOT6
DOT1~DOT7
+24V
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