Xerox 8850 Service Manual

03/2003
2-17
8850/ 510DP
OF-1 Control Panel RAP, OF-2 Power On Self Test
Status Indicator RAPs
OF-1 Control Panel RAP
NOTE: Go to BSD 2.1 while using this RAP, unless otherwise directed.
This RAP is used when the Control Panel does not operate, or when the Control Panel oper-
ates incorrectly.
Initial Actions
• Make sure that AC power is applied to the machine.
• Check that the DC voltage LEDs are lit on the Main PWB (A3).
• Ensure that the 26-conductor ribbon cable, connected between the Main PWB A3J301
and the User Interface PWB A32J1 (located in the Control Panel), is seated fully at each
connector.
Procedure
OF-2 Power On Self Test (POST) RAP
NOTE: Go to BSD 1.2 and BSD 2.1 while using this RAP.
This RAP is used when the logic detects a fault during the Power On Self-test (POST). The
printer does not initialize and the Control Panel displays a 1, 2, 3, 5, 6, or 7.
Initial Actions
• Ensure that the NVRAM are seated fully on the Main PWB, A3.
• Ensure that the 26-conductor ribbon cable, connected between the Main PWB A3J600
and the Control Panel User Interface PWB A32J1, is seated fully at each connector.
Procedure
Table 1 Control Panel Probable Cause / Corrective Action
Control Panel Probable Cause Corrective Action
The Message Display is
blank, no characters are
displayed.
There is an input power
problem.
There is an open circuit in
the ribbon cable between
the Main PWB A3J301 and
the User Interface PWB
A32J1.
There is an internal fault in
the Control Panel or in the
Main PWB A3.
Go to 1.1 AC Power RAP and 1.2
DC Power RAP.
Check for continuity in all wires in
the ribbon cable.
Replace the Control Panel, PL 1.4. If
the problem persists, replace the
Main PWB, A3, PL 1.1.
The Message Display
LEDs are on but no char-
acters are displayed.
There is no +15 VDC to the
Main PWB, A3.
There is no +5 VDC (Bulk) to
the Main PWB, A3.
Go to BSD 1.2 to troubleshoot the
+15 VDC power to the Main PWB,
A3.
Go to BSD 1.2 to troubleshoot the
+5 VDC (Bulk) power to the Main
PWB, A3.
The Message Display
LEDs are on but no char-
acters, random charac-
ters, or black squares
appear.
There is an open circuit in
the ribbon cable between
the Main PWB A3J301 and
the User Interface PWB
A32J1.
There is an internal fault in
the Control Panel or in the
Main PWB A3.
Check for continuity in all wires in
the ribbon cable.
Replace the Control Panel, PL 1.4. If
the problem persists, replace the
Main PWB, A3, PL 1.1.
Table 1 Power On Self Test (POST) Probable Cause / Corrective Action
The number that is
Displayed on the
Control Panel.
Probable Cause Corrective Action
1 or 2 There is a fault in the RAM
memory.
Replace the Main PWB, A3, PL 1.1.
3 The contents of the Control
EPROMs does not agree with
the checksum.
The Main PWB is defective.
Replace both Control EPROMs on
the Main PWB, A3.
Replace the Main PWB, A3, PL 1.1.
5 There is a fault in the Main
PWB, A3.
Replace the Main PWB, A3, PL 1.1.
6 There is a +5 VDC fault in the
Digital-to-Analog Converter .
Replace the Driver PWB, A2, PL
1.1A.
If the problem persists, replace the
Main PWB, A3, PL 1.1.
7 There is a fault in the printer
port output circuitry.
Replace the Main PWB, A3, PL 1.1

Xerox 8850 Specifications

General

Brand	Xerox
Model	8850
Category	Printer
Language	English