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Table 3-5. Printhead Driver Test Points
Transistor
Test Method
Numbers
(Set Meter to Diodes. Check with Printer Power Off.)
Meter Reading
Q2,
Q4,
Q5
Emitter and base are marked on the CO94 MAIN board.
Consistent readings for all
Q6, Q8,
Q9
Check from base to collector, from base to emitter, and
transistors, within
YZ
20%.
Ql
0,
Ql
1, Q12
from emitter to collector. Reverse leads and test again.
Not open and not shorted
between base and collector
Q3,
Q7,
Q13
and base and emitter.
Table 3-6. Carriage and Paper Feed Motor Driver Test Points
CR Motor
Test Method
Driver (IC6) (Set Meter to Diodes.
‘in Numbers Check
with
Printer Power Off.)
Meter Reading
1,
8,
Pins 1 and 18 are marked on board. All odd
Consistent readings from all pins within
f
20%.
ll,and18
pins are on one side, and even are on the Not open and not shorted. (The typical reading
on chip
other. Place + lead on pin 4 (ground) and is 547, but the reading is not as important as
SLA7024M
-
lead on each of the four pins. consistency.)
PF Motor Test Method
Driver
(El)
(Set Meter to Diodes.
‘in
Numbers Check with Printer Power Off.)
Meter Reading
3, 5, 7, and Pins 1 and 10 are marked on board. Place
Consistent readings from all pins within
f
20%
9 on chip
+ lead on pin 1 (ground), and count over
Not open and not shorted. (The typical reading
UPA1476H
to find each of the four pins to be checked. is .672, but consistency is most important.)
Test Method
PF
(Set Meter to Diodes.
Transistor Check with Printer Power Off.)
Meter Reading
Q15
Emitter and base are marked on board.
Consistent readings for all transistors, within
Check from base to collector, from base to
*
20%. Not open and not shorted between
emitter, and from emitter to collector. base and collector and base and emitter.
Reverse leads and test again.
-
--.
-.
3-4
Epson
FX-870/1170