Xerox 3050 Service Manual page 228

1.3
Cooling Fans RAP
(04 Feb 92)
This RAP i s used to locate problems
in
the 26
VDC circuits for the Cooling Fans.
The problem may occur i f there i s a
malfunction i n the fan motors, the wiring to
the motors, the Thermal Controller PWB
(A23A1), or the LVPSI Driver PWB (A2).
NOTE: The component locator drawings and
the circuit diagram are on the following
pages.
Initial
Actions
Check the Connectors A1P1, A1P2,
A1P3, At P4, AZP203, and A23P2 on
the Xerographic Assembly (A23) for
damage, and ensure that the
connectors are seated correctly.
If one of the fans still operates,
perform the following initial check:
Switch off the copier. Connect A1P3 to
A1J4. Connect A1P4 to A1J3. Switch
on the copier. If the same fan still
operates, replace the fan that fails to
operate. Otherwise, perform the
procedure below.
Procedure
Switch off, then switch on the copier.
The Left Cooling Fan operates.
Set the DMM to read
+
26 VDC. Connect
the ( + ) lead to pin 15 of Connector A2
P203. Connect the
(-)
lead to frame
ground. Enter the diagnostic mode.
The voltage at pin 15 goes LOW.
,
I
Replace the LVPSI Driver PWB (A2).
GO
to FLAG 1 and check the wires for
continuity.
1
The wires have continuity.
I
1
Repairthe wirer.
Replace the Thermal Controller PWB
1
(A21A1).
The
Right
Cooling Fan operates.
Set the DMM to read
+
26 VDC. Connect
the (
+
) lead to pin
I5
of Connector A2
P203. Connect the (-) lead to frame
ground. Enter the diagnostic mode.
I
The voltage at pin l 5 goes LOW.
I Y N
C D E
C D E
I
Replace the LVPSI Driver PWB (A2).
Go to FLAG 2 and check the wires for an
open circuit.
The wires have continuity.
V N
I
Repair the wires.
Replace the Thermal Controller PWB
(A23A1).
Enter the diagnostic mode. Enter the code
(09141 and observe the sound of the fans.
The
Cooling Fans operate
at
high speed for
approximately 2 seconds, then operate at
low speed.
I
Replace the LVPSI Driver PWB.
he
Cooling fans operate correctly. Return
to normal operation.
l o / % ?
1.3 Cooling Fans RAP
2-1 36 3050