Lexmark 4227 Service Manual - Page 49

Power failure service check, Diagnostic information, For more information see

Page 49 highlights

4227-300 Power failure service check For more information see "Voltage, ground, and continuity readings" on page 1-2. FRU 1 Operator Panel 2 Power Supply Fuse Action If the operator panel or cable is damaged or disconnected, the machine is completely inoperable, except for the power supply fan noise. If the power LED is not on steady, check the cable continuity and replace the cable or the operator panel. If the printer is completely inoperable, disconnect the power cables from the main logic board (CN11) and the sub logic board (CN1). Turn the power on and measure +5 ± 0.5 V dc at the sub logic board cable CN1-5 and +40 ± 4 V dc at CN1-1 and CN1-2. If there is no voltage, check the internal fuse before replacing the power supply. A 634 Power Failure indicates that the +5 V dc is OK but the +40 V dc is not. Power the printer off, wait 10 seconds, and power back on. If the 634 reappears either the power supply has failed or there is a short in a motor that uses +40 V dc. Diagnostic information 2-25

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Diagnostic information
2-25
4227-300
Power failure service check
For more information see
“Voltage, ground, and continuity readings”
on page 1-2
.
FRU
Action
1
Operator Panel
If the operator panel or cable is damaged or
disconnected, the machine is completely
inoperable, except for the power supply fan
noise.
If the power LED is not on steady, check the
cable continuity and replace the cable or the
operator panel.
2
Power Supply
Fuse
If the printer is completely inoperable,
disconnect the power cables from the main
logic board (CN11) and the sub logic board
(CN1).
Turn the power on and measure
+5 ±
0.
5 V dc at the sub logic board cable
CN1-5 and +40 ± 4 V dc at CN1-1 and CN1-2.
If there is no voltage, check the internal fuse
before replacing the power supply.
A 634 Power Failure indicates that the +5 V dc
is OK but the +40 V dc is not. Power the printer
off, wait 10 seconds, and power back on. If the
634 reappears either the power supply has
failed or there is a short in a motor that uses
+40 V dc.