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MX-7500N  TROUBLESHOOTING  7 – 53

 

 

 

 

 

 

 

Trouble content

Exhaust fan motor abnormality

Detail

PCU

Cause

Motor lock
Motor RPM abnormality
Over current to the motor
Harness and connector connection trouble
A3 2-stage LCT control PWB trouble

Check & Remedy

Use SIM04-03 to check the operation of the exhaust 
fan motor.
Check connection of the harness and the connector.
Replace the A3 2-stage LCT controller PWB.

Trouble content

The thermistor is open.

Detail

PCU

Cause

Warm air heater (thermistor) trouble
A3 2-stage LCT control PWB trouble
Warm air heater harness and connector connection 
trouble

Check & Remedy

Check the harness and the connector from the warm 
air heater (thermistor) to the A3 2-stage LCT control 
PWB.

Trouble content

The temperature does not reach the specified level 
within the specified time after turning ON the power 
relay.

Detail

PCU

Cause

Warm air heater (thermistor) trouble
Warm air heater trouble
Warm air heater harness and connector connection 
trouble
A3 2-stage LCT control PWB trouble
Thermostat trouble.
AC power trouble
Insertion detection switch 2 trouble
Heater relay PWB trouble

Check & Remedy

Check the warm air heater (thermistor) and its har-
ness.
Check the thermistor input circuit section of the A3 2- 
stage LCT control PWB.
Check for disconnection of the warm air heater and 
the thermostat.
Check the insertion detection switch 2.
Check the heater relay PWB.
Check the heater control circuit of the AC PWB and 
that of the A3 2- stage LCT control PWB.

Trouble content

The warm air heater temperature exceeds the 
specified level.

Detail

PCU

Cause

Warm air heater (thermistor) trouble
A3 2-stage LCT control PWB trouble
Warm air heater harness and connector connection 
trouble
Heater relay PWB trouble

Check & Remedy

Check the warm air heater (thermistor) and its har-
ness.
Check the thermistor input circuit section of the A3 2- 
stage LCT control PWB.
Check the heater relay PWB.
Check the heater control circuit of the A3 2-stage LCT 
control PWB.

Trouble content

The thermistor is open.

Detail

PCU

Cause

Thermistor trouble.
A3 2-stage LCT control PWB trouble
Connector connection trouble

Check & Remedy

Check connection of the harness and the connector 
from the thermistor to the A3 2-stage LCT control 
PWB.

Trouble content

The temperature does not reach the specified level 
within the specified time after turning ON the power 
relay.

Detail

PCU

Cause

Thermistor trouble.
Warm air heater trouble
Warm air heater harness and connector connection 
trouble
A3 2-stage LCT control PWB trouble
Thermostat trouble.
AC power trouble
Insertion detection switch 2 trouble
Heater relay PWB trouble

Check & Remedy

Check the thermistor and its harness.
Check the thermistor input circuit section of the A3 2- 
stage LCT control PWB.
Check for disconnection of the warm air heater and 
the thermostat.
Check the insertion detection switch 2.
Check the heater relay PWB.
Check the heater control circuit of the AC PWB and
that of the A3 2-stage LCT control PWB.

Trouble content

The temperature at the warm air outlet port exceeds 
the specified level.

Detail

PCU

Cause

Thermistor trouble.
Warm air heater harness and connector connection 
trouble
Heater relay PWB trouble
A3 2-stage LCT control PWB trouble

Check & Remedy

Check the thermistor and its harness.
Check the thermistor input circuit section of the A3 2- 
stage LCT control PWB.
Check the heater relay PWB.
Check the heater control circuit of the A3 2-stage LCT 
control PWB.

MX-7500N  TROUBLESHOOTING  7 – 54

Two-digit numbers with double parentheses are added to E7-91 - 94 error codes recorded in SIM22-6 indicate the detailed contents of the
errors.

The number in each digit has its own meaning.

(Example) E7-91(**)

The upper digit of the added code indicates the job kind at the occurrence of the error.

The lower digit of the added code indicates the kind and the content of the abnormality or the result of the automatic memory check executed
when the abnormality is detected.

: Added code indicating that the memory and its peripheral must be focused for check in case of an error.

-  : Added code without generating

E7-91

0*

Other

•FAX (Internet FAX) reception 

print (Other than long size 
images)

1*

JPEG

2*

JBIG

3*

Mxx1ch

4*

Mxx4ch

5*

Other

•FAX (Internet FAX) reception 

print 
(Long size images)

6*

JPEG

7*

JBIG

8*

Mxx1ch

9*

Mxx4ch

A* - F*

Not Used

E7-92

0*

Other

•OC copy (in Non ERDH)

1*

JPEG

2*

JBIG

3*

Mxx1ch

4*

Mxx4ch

5* - F*

Not Used

E7-93

0*

Other

•Copy print (in ERDH)
•Copy composing system 

function (Custom Stamp, 
Water mark)

1*

JPEG

2*

JBIG

3*

Mxx1ch

4*

Mxx4ch

5*

Other

•Image send
•Document filing
•Preview display

6*

JPEG

7*

JBIG

8*

Mxx1ch

9*

Mxx4ch

A*

Other

•GDI/PCL printer print
•Copy composing system 

function (Custom Stamp, 
Water mark)

B*

JPEG

C*

JBIG

D*

Mxx1ch

E*

Mxx4ch

F*

Not Used

E7-94

0*

Other

•Backup restore 

(Filing data import)

1*

JPEG

2*

JBIG

3*

Mxx1ch

4*

Mxx4ch

5* - F*

Not Used

The upper digit of the 

added code

Error detection circuit

1*, 6*, B*

JPEG

-

-

2*, 7*, C*

JBIG

-

-

-

-

3*, 8*, D*

Mxx1ch

-

-

-

-

-

-

4*, 9*, E*

Mxx4ch

-

-

-

-

-

-

MX-7500N  TROUBLESHOOTING  7 – 55

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.

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 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.

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.

MX-7500N  TROUBLESHOOTING  7 – 56

When the machine cannot be booted, the content and the cause of
the error can be presumed by checking the status of LED (2) of the
MFP PWB shown in the figure below. 

*

: LED ON / 

* In case of an error, the LED's flash as shown in the above table.

*

: LED ON / 

CPU initial setting

Reus ASIC trouble

Memory adjustment, Memory 
check, etc.

Memory and its 
peripheral circuit trouble

Interruption-related initialization

Reus ASIC trouble

PCIe initialization

PCIe peripheral circuit 
trouble (Intel Atom/PCIe 
Switch, etc.)

Basic device initialization

Reus ASIC trouble

SD card initialization

Reus ASIC trouble
SD card trouble

OS initialization (1)

Reus ASIC trouble

Timer enabling

Reus ASIC trouble

Serial driver enabling
I2C driver enabling

Reus ASIC trouble

RTC initialization

Reus ASIC trouble

Image process IP initialization

Reus ASIC trouble

OS initialization (2)

Reus ASIC trouble

Main process

Reus ASIC trouble

Memory combination error

Memory trouble

Memory with operations 
unguaranteed

Memory trouble

SPD set value error (Memory 
trouble)

Memory trouble

SPD read error

Memory trouble

Internal set value error

Memory trouble

#&

3$

MFT_L

Manual feed tray paper feed JAM 
(100K for the paper feed counter)*

1

TRAY1_L

Tray 1 paper feed JAM 
(100K for the paper feed counter)*

1

TRAY2_L

Tray 2 paper feed JAM 
(100K for the paper feed counter)*

1

TRAY3_L

Tray 3 paper feed JAM 
(100K for the paper feed counter)*

1

TRAY4_L

Tray 4 paper feed JAM 
(100K for the paper feed counter)*

1

LCC_L

Side A4LCC paper feed JAM 
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LCT1_1_L

Multi-stage LCT tray 1 paper feed JAM 
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LCT1_2_L

Multi-stage LCT tray 2 paper feed JAM 
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LCT1_3_L

Multi-stage LCT tray 3 paper feed JAM 
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LCT2_1_L

Expanded multi-stage LCT tray 1 paper feed JAM 
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Expanded multi-stage LCT tray 3 paper feed JAM 
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INSTR1_L

Inserter tray 1 paper feed JAM 
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MFT

Manual feed tray paper feed JAM (MPFD not-reached)

MPFD_S

MPFD remaining JAM

TRAY1

Tandem tray 1

T1PPD1_S1

T1PPD1 remaining JAM

T1PPD2_N1

Tandem tray 1 paper feed JAM 
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T1PPD2_S1

T1PPD2 remaining JAM

TRAY2

Tandem tray 2 paper feed JAM 
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T2PPD1_N3

T2PPD1 not-reached JAM (cassette 3 paper feed 
paper)

T2PPD1_N4

T2PPD1 not-reached JAM (cassette 4 paper feed 
paper)

T2PPD1_S2

T2PPD1 remaining JAM (cassette 2 paper feed paper)

T2PPD1_S3

T2PPD1 remaining JAM (cassette 3 paper feed paper)

T2PPD1_S4

T2PPD1 remaining JAM (cassette 4 paper feed paper)

TRAY3

Cassette 3 paper feed JAM (C3PFD not-reached JAM)

C3PFD_N4

C3PFD not-reached JAM (cassette 4 paper feed paper)

C3PFD_S3

C3PFD remaining JAM (cassette 3 paper feed paper)

C3PFD_S4

C3PFD remaining JAM (cassette 4 paper feed paper)

TRAY4

Cassette 4 paper feed JAM (C4PFD not-reached JAM)

C4PFD_S4

C4PFD remaining JAM (cassette 4 paper feed paper)

LPPD1_NL

LPPD not-reached JAM 
(side A4/A3LCC paper feed paper)

LPPD1_NL11

LPPD not-reached JAM 
(large capacity paper feed tray 1 paper feed paper)

LPPD1_NL12

LPPD not-reached JAM 
(large capacity paper feed tray 2 paper feed paper)

LPPD1_NL13

LPPD not-reached JAM 
(large capacity paper feed tray 3 paper feed paper)

LPPD1_NL21

LPPD not-reached JAM 
(large capacity paper feed tray 4 paper feed paper)

LPPD1_NL22

LPPD not-reached JAM 
(large capacity paper feed tray 5 paper feed paper)

LPPD1_NL23

LPPD not-reached JAM 
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LPPD1_NLM

LPPD not-reached JAM 
(large capacity paper feed tray manual paper feed 
paper)