--- In email@example.com
, rgm0737@c... wrote:
> This printer after warmup gives the error message "E31". I don't
> any paper jams, but the heater is not getting warm. What is
> error? Thanks in advance for help.
This helped me out with a 4420, and I've heard the 4430 can suffer
TROUBLE REPORTED: "CALL SERVICE E31"
These days numerous Panasonic 4420 laser printers are displaying the
message "CALL SERVICE E31." A quick look in the Panasonic service
manual and you will discover that an E31 Error is a fuser
malfunction. In other words, the fusing assembly, for whatever
reason, failed to reach the correct operating temperature in the
Fuser assembly errors of this kind are not uncommon to the laser
printer technician. In most cases, replacement of the fusing assembly
is all that is needed to correct this error. This is not the case
with the Panasonic 4420. Laser Wizard has discovered that 98% of the
time, a cold solder joint within the power supply is the culprit for
A cold solder joint is when a small break in the solder connection
forms, resulting in an open connection. This will look like a small
ring within the cone of the solder connection. A magnifying glass may
be needed to see this ring. A few of the more common reasons for this
condition are: insufficient heat during soldering, improper removal
of the flux, tarnished connectors and PC board pads, and
crystallization of the solder from age and usage.
*Always unplug the machine before beginning service.*
Before you begin servicing the Panasonic 4420 laser printer, remove
both the developer and drum unit with great care. Place the drum unit
on a clean surface (paper lined table top), out of the light, and
such that the drum is not making contact with anything.
1 Remove the paper tray and front panel.
2 Disconnect the top connector from the power supply; with a
multimeter, check the resistance between the black and white wire.
3 If the circuit is open, the fuser needs to be replaced. If
resistance is found, the fault lies within the power supply, which
must be removed to be repaired.
4 Remove the power supply board from the protective metal case.
5 Check the solder connection of CN205, CN202, and CN207 on the power
supply board. CN205 pin 6 and/or pin 1 will most likely be defective.
Repair: Remove the defective and old solder. Clean both the PC board
pad and the connector with an appropriate cleaning solvent. The
connector does not need to be removed from the PC board to do this.
Now you can re-solder the connector. The pins of this connector are
larger than normal connector pins. For this reason they will act like
a heat sink; make sure that the pin and PC board pad are hot enough
to produce a good solder connection. In addition to repairing the
defective solder connection, I suggest that you touch up the solder
joints on all the pins of CN205, CN202, and CN207 as well. If the run
or pad on the PC board has become burned preventing you from re-
soldering a pin of the connector to the PC board, a 20-gauge
insulated wire may be used to supplement the run of the PC board.
Solder the wire first to the damaged pin of the connector, then to
the closest component within that run.
6 Now simply reassemble the power supply, install it in the laser
printer and test.
CONGRATULATIONS, you have just FIXED the E31 error, not just
exchanged parts. After your second or third time repairing this
error, it should only take you thirty to forty minutes to perform
this repair from start to finish. Because of the amount of screws
needing to be removed and installed to perform this repair, a power
screwdriver will help to reduce your repair time.
TIP: To provide you with more working room, the top on the Panasonic
4420 can be opened to a full 90 degrees. To do this, locate a lever
with a green cap along the bottom right side of the fuser assembly.
Pull the top of the printer down slightly to take the pressure off
the hinge stop, move this lever to the left and open the cover to a
full 90 degrees.
Hope it helped