Epson Stylus Color 980 Service Manual

EPSON Stylus Color 980 Revision A
Operating Principles Electrical Circuit Operation Principles 72
2.3.7 Cooling Fan Driver Circuit
Since this printer drives a large number of PZT elements (total of 480
nozzles) with a high drive frequency (maximum 32.4 K Hz), heat
radiated around the printheads and the trapezoid waveform production
circuit on the C380 main board is considerably large compared to other
printers. Therefore a thermistor is attached to the heat sink fixed to the
trapezoid waveform production transistors to prevent the trapezoid
waveform production transistors (Q3 - Q6) and adjacent HIC from
operating abnormally due to high temperature. When the thermistor
detects abnormally high temperature, the printer turns the cooling fan
on to forcibly blow out heat from the lower case. Figure 2-19 shows the
cooling fan driver circuit block diagram. Table 2-19 shows how the
signals output from the ASIC and corresponding fan conditions.
Figure 2-19. Cooling Fan Driver Circuit Block Diagram
Table 2-19. Cooling Fan Control by the ASIC (IC2)
Figure 2-20 shows the main routine of the cooling fan drive.
Figure 2-20. Main Routine of the Cooling Fan Drive
ASIC (IC2, 176- pin) condition Cooling fan condition
High (5 VDC) On
Low (0 VDC) Off
+42
6.8
CN13
GND
2
1
+35
39 K
E05B59(IC 2)
176
FAN
FAN
F6
D rops to 35 V.
Start
YES
YES
Error 1
NO
YES
Fan On
YES
Fan Off
NO
NO
YES
NO
Error 1
Return to the Start.
t1 = Heat sink temperature on the C380 main board
t2 = TH1 temperature on the C380 main borad.
Is
the fan
rotating?
t1 >/= 50
°
C
or
t2 >/= 55
°
C
t1 >/= 60
°
C
or
t2 >/= 60
°
C
t1 >/= 40
°
C
or
t2 >/= 50
°
C
t1 >/= 36
°
C
or
t2 >/= 42
°
C
NO

Epson Stylus Color 980 Specifications

General

Brand	Epson
Model	Stylus Color 980
Category	Printer
Language	English