Epson DLQ-3000 Service Manual page 111

5.4 BOARD ASSY., C124 MAIN REPAIR
Table 5-9. describes the repair procedure for the BOARD ASSY., C124 MAIN board.
Table 5-9. BOARD ASSY., C124 MAIN Repair
Trouble
The reset
circuit
The
operates
reset
abnormally.
signal is
not
signal is not
generated.
Does
not
The
operate
CLOCK
at all.
signal does
The
CPU
The flash
does not
operate.
The CPU is
Goes to
"Fatal
an error
error"
state.
circuit is
Cause
Check that IC14 pin 1 goes LOW shortly
after the power is turned on.
The reset signal is generated from signal
If the pin goes LOW, refer to the section
entitled "The CPU does not operate.".
Check that the +5V is normal. Then, check
the connector of CN1 O pin 3 and 4.
Check the clock waveform at pins 11 and
12 of ICI o.
See Figure 5-11.
Reload the Printer Control Program.
Check that the waveforms at pin 112
ICI O are changing.
bad.
See Figure 5-12.
Measure the reference voltage of the
sensor (approx. 35V) at pin 63 of IC1 O.
The +35V
If the voltage is normal, the CPU: IC1O is
monitor
circuit is
bad. the IC15 or IC22, and the peripheral
components are bad.
Check the CR motor control pulse at pins
The
66,67,68 and 69 of IC1 O.
carriage
Check the CR motor drive pulse at pins 1,
motor
8,11, and 18 (CRA to CR/B) of IC1.
control
Check the common voltage at pin 1 of
connector CN 14.
bad.
See Figure 5-13. (phase data)
Item to Check
Troubleshooting
Troubleshooting
Replace IC14.
Replace the
BOARD
SUPPLY.
Replace the
BOARD
SUPPLY or CR1.
Replace the
BOARD
Replace the
Replace the
BOARD
Otherwise,
replace IC15,
peripheral
components.
Replace the
BOARD
Otherwise,
replace IC1 and
the peripheral
components.
S-15