Xerox 3050 Service Manual page 284

user
temperature and an -overtemperature
condition has caused the Thermal Fuse
(A23A1 F1) t o open.
NOTE: The circuit diagram and the
component locator drawings are on the
following pages.
Initial Actions
WARNING
Dangerous Voltage'.
Ensure that Connectors A4P1 and
A4P2 on the 26 VDC Bulk Power
Supply, A2P210 AND A2P203 on the
LVPSI Driver PWB (A2), A23A1P5 on
the Thermal Controller PWB (A23A1),
and A23PlJ2 are correctly installed and
fully seated.
Ensure that all interlock switches are
closed.
LL.43 Fuser Overtemperature
RAP
The Status Code LL.43 is displayed when the
logic detects that there is a problem with the
lA
Procedure
Switch on the copier.
Both Cooling Fans operate.
Y N
I
Go t o the 1.3 Cooling Fen RAP.
WITaglMOD 6: Go t o "A" in second column.
CR24 on the LVPSI Driver PWB is lit.
I
GO to the 1.4 Main Power Interlock RAP.
D S ~
on the 26 VDC Bulk Power Supply is lit.
Y N
A B
Set the DMM t o read ACH. There is ACH at
Bulk Power Supply (A4) connector A4 PI J2.
Y N
I
Replace the 26 VDC Bulk Supply.
CR27 on the LVPSI Driver PWB is lit.
Go to the 1.4 Main Power Interlock
i
: . .
Go t o FLAG 4 and check the wires for an
open circuit.
"A" WITagIMOD 6: Continue from this
point.
There is an open circuit.
Y N
Replace the 26 VDC Bulk Power Supply
1
(Ad).
Repair the wires.
Set the DMM to read 26 VDC. Connect the
(
+
)
probe t o Connector A2P203-4. Connect the
(-)
probe to Connector A2P2 10-2.
26 VDC is present.
I
Replace the LVPSIDriver PWB (A2).
Connect the (
+
) probe t o Connector
A2P203-2.
26 VDC is present.
Disconnect A23AlP5. Set the DMM to
read continuity. Connect the
(
+
) probe t o
A23A1J5-4. Connect the
(-)
probe t o
A23Al J5-2.
I
There is continuity.
Y N
C D E
open circuit.
The wires have continuity.
Repair the wires.
i N
Switch off the copier, and disconnect
the Power Cord. Replace the
Thermal Fuse (A23A1 F1). Disconnect
the blue and white wires from the
Triac (Q1). Set the DMM to measure
2K ohms, and measure the resistance
across the connections from which
the wires were removed. If the
resistance is not infinite, replace the
triac. Measure the resistance from
each terminal on the triac t o frame
ground. If the resistance is not
infinite, replace the triac. Reconnect
the wires. Reconnect the power
cord.
o to FLAG 2 and check the wires for an
F
Switch off the copier. Disconnect
A23A1P1 on the Thermal Controller
PWB. Set the DMM to read 200K ohms.
Go to Flag 4 and check the resistance.
C D E
G
The resistance is less than 200K ohms.
I
Replace the Thermal Controller PWB
A23A1.
Go to FLAG
4
and check the wires for an
open circuit.
LL.43 Fuser Overtemperature RAP