15
4
Trouble shooting
Phenomenon
condition
Considerable cause
Check point/method
Remedy
AC power is not supplied
AC power is not applied to
switching power supply.
Is AC power plug connected to outlet?
Is outlet voltage normal?
Is fuse (primary side of switching
Power supply?
Is 24V output from secondary side of
switching power supply?
Connect the plug to outlet.
Replace the fuse
Replace the switching power supply.
Is DC power voltage
normal?
+24V is not generated
+5V is not generated.
Does collector of PQ1 output oscillation
wave ?
Is PD11 defect?
Replace PQ1
Replace PD11
Replace converter transformer.
Crystal is not oscillating.
Check wave form pin 20 and
Pin 22 of U17(frequency 20MHz)
Replace crystal(x1)
Replace U17
Machine
doesn’t work
at all
Printer doesn’t work
after power on
The levels of PF lines don’t
become “H”
Is D20 defect?
Are
Replace D20
Replace U27 and U33
Date/time
data fails.
Date doesn’t
increment.
Date /time data
doesn’t increment
correctly
Crystal(x2:32.768kHz) is
not oscillating properly.
Check wave form of pin 17 and pin 18 of
U17(frequency:32.768kHz)
Replace crystal(X2)
Buzzer
doesn’t sound
Trouble in buzzer circuit.
When pin 8(P146)of U17 output “H”,
buzzer is driven.
Is Q1 defect?.
Replace the buzzer.
Replace Q1
Drawer is not
opened
Drawer solenoid
doesn’t operate.
Trouble in drawer circuit
When pin 29(P145)of U17 output “H”,
drawer solenoid is driven.
Is Q6 defect?.
Replace Q6
Abnormal
print out
Printed character is
Not desired.
The level of timing signal is
not stable.
Printer is defect.
Is the signal level of pin 1(U13) stable?
Replace U13
