MX-6240N, MX-7040N (serv.man26). Section 7 Troubleshooting - Updated November 2012 - Sharp Copying Equipment Service Manual (repair manual). Page 58

MX-7040N  TROUBLESHOOTING  7 – 58

NOTE: Since the automatic memory check executed when E7-91 -

94 occurs is a simplified check, it cannot detect an abnor-
mality with absolute certainty.

If the added code is (*1), there may be a memory abnor-
mality. Even if it is not (*1), however, it cannot be said that
there is no abnormality around the memory.

NOTE: When there is an abnormality around the HDD, E7-03 may

occur.

If error E7-91 - 94 as well as E7-03 occurs, there is a high
possibility that the error can be removed by replacing the
HDD and the MFPC PWB.

[Trouble content]
If nothing is displayed when the machine is booted, the error code
cannot be checked and the cause is hard to identify.

One of the causes may be an abnormality in the boot program of
the SD card. To check that, the following method is used.

[Check method]
Check to confirm that the LED (red) (1) under the CPU heat sink on
the MFP PWB shown in the figure below is lighted when the power
is supplied.

If the LED is lighted, it is judged as an abnormality of the SD card.
[Countermeasures]
1)

Replace the SD card with a new one. (Be sure to use a service
part.)

2)

Upgrade the firmware to the latest version.

3)

Use SIIM66-62 to backup the FAX reception data from the
HDD to a USB memory device. (If there is no FAX reception
data, this procedure is not required.) (The FAX reception data
are backed up in the PDF format. Supply the date to the user.)

4)

Use SIM66-10 to clear the FAX and image send memory.
(Ensure consistency between the HDD data and the image
related memory.)

Cause

In case of E7-91 - 94, the DIMM memory (DRAM) is 
automatically read/written to perform a simplified 
check. If an abnormality is detected in that case, the 
added code becomes (*1).
Therefore, there is a strong possibility that an 
abnormality lies around the memory.

Check and remedy

• Check the installing state of the DIMM memory 

and the MFPC PWB to insure that there is no 
abnormality. (Disconnect and connect the DIMM 
memory and the MFPC PWB to check to insure 
that there is no error occurring again.)

• Use SIM60-01 (Memory read/write check) to 

check to insure that no error occurs.

• Replace the DIMM memory.
• Replace the MFPC PWB.

Cause

Mostly because the data inputted to the ASIC for 
decoding are broken for some reasons.
There is an abnormality in the process of read/write 
of the process data in the memory or the hard disk.
A great noise unexpectedly generated may be the 
cause.
For the cases of FAX or Internet FAX reception data, 
when broken data are saved, printing is performed 
every time when the machine is booted, generating 
an error repeatedly. (E7-91)
(To clear the received data, execute SIM66-10.)

Check and remedy

• Check the DIMM memory, the MFPC PWB, and 

the HDD to insure that there is no abnormality.

• When the job at occurrence of an error is FAX 

(E7-91), check the installing state of the FAX 
control PWB and the SC CARD PWB.

• Perform SIM60-01 (Memory read/write check) to 

insure that there is no NG.

• Perform SIM62-02 and SIM62-03 (HDD read/

write check) to insure that there is no NG. (It is not 
required, however, when the job at occurrence of 
an error is FAX.)

• Check the installing state of the DIMM memory 

and the MFPC PWB to insure that there is no 
abnormality. (Disconnect and connect the DIMM 
memory and the MFPC PWB to check to insure 
that there is no error occurring again.)

• Replace the HDD.
• Replace the FAX control PWB.
• Replace the DIMM memory.
• Replace the MFPC PWB.
• Replace the SD card.