Troubleshooting - Casio DL-220LA(GY) Service Manual & Parts List

4. TROUBLESHOOTING

Trouble
1) Does not work • Defective power transformer
at all.
• Defective LSI
2) No display. • No voltage at VF1, VF2
• No digit signal or no segment
signal
• Defective display tube
• Poor voltage VM
3) No print.
• Defective motor
• Defective LSI
4) Poor display.
• Short or open circuits
between digit signals and
segment signals.
• Defective display tube
5) Poor printing • Timing signal is bad.
• Motor does
not stop.
• Defective printer magnet
• Missing of
digits
Refer to the printer service manual published separately.
Cause
Secondary voltage of
transformer
Waveforms of each pin
VF1, VF2
Signal D1 ~
Between LSI and
display tube
— 4 —
Checkpoint
VDD, VSS, VM, VF1, and
VF2 are OK?
Check the pulse signals
from LSI.
S1 ~
If VF1, VF2, Digit and
Segment signals are OK.
VM=11V (while printing)
Check detector of printer
block and timing signal.
Note