Notes On Troubleshooting - Epson EPL-N3000 Service Manual

EPSON EPL-N3000/AcuLaser M4000N

3.1.5 Notes on Troubleshooting

The troubleshooting method described here assumes there is no malfunction in the
printer controller (Main Board). If you can not fix a problem even by following the
troubleshooting procedure, you are advised to replace the printer controller with a
normal one and then follow the same procedure.
If you can not recover the printer from the trouble even with the printer controller
replaced, replace the "Parts that can be the cource of this error" with new ones in
order one by one and repeat operation checks.
Some normal components may be required as troubleshooting tools to identify the
cause of the trouble. You are advised to have a spare HVPS/MCU, LVPS, FUSER
ASSY, BTR ASSY, and Y/M/C/K Imaging cartridges.
Be sure to unplug the POWER CORD before starting troubleshooting work except
when turning power ON is needed. With the power cord connected, never touch
any live parts unnecessarily.
Conventions used to represent connectors are as follows:
P/J12: Connector (P/J12) with the Plug and Jack connected to each other.
P12: Plug side with the connector (P/J12) disconnected
(This does not apply to direct connection to a circuit board)
J12: Jack side with the connector (P/J12) disconnected
(This does not apply to direct connection to a circuit board)
Unless otherwise specified, measure the voltage with the Plug and
C H E C K
Jack connected to each other.
P O I N T
↔
When "P/J1-2 P/J3-4", for instance, is referred to in any diagnosis item, make
measurement by placing the positive (+) probe of your meter on the pin 2 of P/J1
and the negative (-) probe on the pin 4 of P/J3.
↔
When "P/J1 P/J2", for instance, is referred to in any diagnosis item, make
measurement between every pair of terminals of the P/J1 and P/J2 by consulting
"7.2 Wiring Diagrams and Signal Information" (p.410)
Troubleshooting
.
Overview
↔
When "P/J1-2 P/J3-4", for instance, is referred to in any diagnosis item for
voltage measurement, the negative terminal "P/J3-4" is always of AG (Analog
Ground), SG (Signal Ground) or RTN (Return).
Therefore, first make certain that actually there is continuity between AGs,
between SGs and between RTNs. Then you are allowed to connect the negative (-)
probe of your meter not to "P/J3-4PIN" but to another AG, SG or RTN pin.
However, AG, SG and RTN are not all of the same level, so you must be careful
not to confuse them.
Use a dedicated tool to measure the voltage of the small connector. Handle the tool
carefully as its front end is sharp.
Measure the voltage with the Imaging Cartridge, BTR ASSY and paper tray
mounted, with the COVER TOP ASSY, FUSER ASSY and COVER REAR
closed and with the power turned ON, as long as these conditions do not obstruct
the measuring work.
All voltage values given in the diagnosis items are approximate values. Actually
measured values different somewhat from, but deemed close to, the given values
should be accepted.
Remember that diagnosis items do not provide any description on removal of parts
which are supposed to be always removed, and work operations which are
supposed to be done, to perform servicing work indicated in diagnosis items.
"Replacement" referred to in diagnosis items lists the parts which can be the
source of the trouble and signifies that the parts or the assemblies (HIGH ASSY)
containing those parts should be replaced with normal ones one by one and
checking should be repeated.
In the FIP, the first stage of the feeder using paper trays at the bottom of the printer
is described as "Tray 1" and the second stage as "Tray 2", and the first stage of the
Option 550 Paper Feeder as "Tray 3" and the second stage as "Tray 4".
Revision C
66
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