5. TROUBLESHOOTING
TroubleCauseCheckpointNote
1) Does not workY Defective power transformerSecondary voltageVDD, VSS, VM, VF1, and
at all.of transformerVF2 are OK?
Y Defective LSIWaveforms of each
pin
2) No display.Y No voltage at VF1, VF2VF1, VF2
Y No digit signal or no segmentSignal D1 ~Check the pulse signals
signalS1 ~from LSI.
Y Defective display tubeIf VF1, VF2, Digit and
Segment signals are OK.
3) No print.VM = 11 V?5 % (while print-Y Poor voltage VM
ing)
Y Defective motor
4) Poor display.Y Defective LSI
Y Short or open circuits betweenBetween LSI and
digit signals and segment sig-display tube
nals.
Y Defective display tube
5) Poor printingY Timing signal is bad.Check detector of printer
Y Motor doesblock and timing signal.
not stop.
Y Missing ofY Defective printer magnet
digits.
Y Refer to the printer service manual published separately.
N 4 N |