Lexmark T 430, Service Manual

Page: 75 / 249

Diagnostic information
2-41
4048-1xx
Hot fuser service check
Cold fuser service check
FRU Action
Fuser assembly
LVPS Unplug the printer and disconnect the fuser
heater cable from the LVPS card connector
(CN3). See
“Low voltage power supply
(LVPS)” on page 5-7 for more information.
Check for continuity across the fuser heater
(pins #1 and #3 or outer pins). If there is no
continuity, replace the fuser assembly. See
“Fuser assembly removal” on page 4-26 . If
there is continuity, follow these steps:
1. Reconnect the fuser heater cable.
2. Replug and turn the printer on. Measure
the voltage between the connectors on
the back of the switch. It should match the
line voltage.
3. If line voltage is not present, replace the
LVPS. Make sure the fuser thermistor is
correctly connected to the controller card
(J18).
Fuser assembly If the fuser heater comes on and a fuser failure
error code displays, be sure the thermistor is
firmly seated in connector J18 on the controller
card assembly. (The thermistor cable goes
through the frame by way of a connector.)
Unplug the printer and disconnect the
thermistor cable from the controller card (J18).
Measure the resistance of the thermistor. The
resistance measures approximately 240K to
400K ohms when cool (approximately 40°C or
104°F) and 1.5K to 3K ohms hot (immediately
after running a printout).
Replace the fuser assembly as necessary.
FRU Action
Fuser assembly Unplug the printer and measure the resistance
of the thermistor. The resistance measures
240K to 400K ohms when cool (approximately
40°C or 104°F) and 1.5K to 3K ohms hot.
Replace the fuser assembly as necessary.