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AR-M550/M620  DETAILS OF EACH SECTION  6 - 108

• Engage the bearings F/R with the pressure lever concaves and pull

out the paper from the scraper side.

• When closing the unit, first close the upper unit from the above in

order to prevent against deform of the scraper.

1) Remove the fusing unit. (See “a. Fusing unit” in this section)

2) Open the fusing unit.

3) Remove the pressure roller unit.

4) Remove the fusing cleaning scraper.

• Clean and remove paper dust and toner remained in the concave of

the scraper holder.

AR-M550/M620  DETAILS OF EACH SECTION  6 - 109

1) Remove the fusing unit. (See “a. Fusing unit” in this section)

2) Release the pressure. (See “a-4. Heater lamp 1” in this section)

3) Remove the blue screw to open the fusing unit.

4) Clean the paper guide.

5) Remove the CL brush from the paper guide.

1) Remove the fusing unit. (See “a. Fusing unit” in this section)

2) Release the pressure. (See “a-4. Heater lamp 1” in this section)

3) Lay the unit on its side to prevent paper dust from dispersing, and

remove the lower cover.

4) Clean paper dust.

5) Remove the spring.

6) Remove the thermostat terminals.

7) Remove the thermistor.

AR-M550/M620  DETAILS OF EACH SECTION  6 - 110

8) Remove the No. 2 heating roller unit.

9) Remove the lamp fixture.

10) Remove the sub heater lamp.

11) Remove the ring, and remove the second heater roller bearing and

the second heater roller.

1) Remove the fusing unit. (See “a. Fusing unit” in this section)

2) Remove the thermostat 1 (A) and the thermostat 2 (B).

1) Remove the fusing unit. (See “a. Fusing unit” in this section)

2) Remove the heating unit.

3) Remove the thermostat 3.

1) Remove the fusing unit. (See “a. Fusing unit” in this section)

2) Lay the unit on its side to prevent paper dust from dispersing, and

remove the lower cover. (See “a-11. CL brush” in this section)

3) Clean paper dust. (See “a-15. Sub heater lamp” in this section)

4) Remove the second heating roller cleaning holding plate.

5) Do not lay the unit with the discharge brush on the lower side.

6) Remove the cleaning sheet.

• If the roller is cooled down, toner may be hardened to prevent

removing.

• Since cleaning is performed by applying a pressure by the

spring, be careful not to deform it.

• If copy dirt is heavy, replace the cleaning sheet with a new one.

A

B

AR-M550/M620  DETAILS OF EACH SECTION  6 - 111

Sheet documents are automatically fed and transported for continuous
scanning.

The front and the back surfaces of duplex sheet documents can be
scanned at a time.

To increase the document replacement speed, preliminary feed is per-
formed for the second and the following documents when two or more
documents of A4/Letter size or smaller are scanned.

For this purpose, each transport roller is provided with a clutch to per-
form independent control.

In addition, an electromagnetic brake is employed for each transport
roller because it reduces the motor load when compared with the
mechanical brake.

No.

Name

Function

1

Document tray

Paper feed tray for documents. Max. loading capacity of documents: 150 sheets (80g/m²) or 19.5mm or less

2

Pickup roller

Picks up a document and transports it to the document feed roller. 

3

Document feed roller

Feeds documents. 

4

Separation roller

Separates paper to prevent against double feed.

5

No. 1 resist roller

Performs document feed resist. 

6

Transport roller 1 (Drive)

Transports documents. 

7

Transport roller 2 (Drive)

Transports documents.

8

No. 2 resist roller

Makes synchronization between the document lead edge and the scan start position. 

9

Paper exit roller (Drive)

Discharges documents. 

10

CIS unit

Scans the back surface of a document. 

1

2

3

5

4

6

7

8

9

10

Default 37mm (102.8ms)
SIM adjustment 
(Image lead edge alignment)

Default 26mm (72.3ms)
SIM adjustment (Image rear edge alignment)

10 ms

923 ms

50 ms

(18mm)

50 ms

(18mm)

50 ms

167 ms

(60mm)

67 ms

SIM adjustment

67 ms (24mm)

SIM adjustment

167 ms

(60mm)

30 ms

50 ms

(18mm)

10 ms

36 ms

SIM adjustment

50 ms

(18mm)

10 ms

5 ms

10 ms

10 ms

5 ms

5 ms

10 ms

5 ms

Timer from SPF motor ON

SPFC
Document feed clutch

SPFMCLK1, 2

SPFFAN
Fan motor

COPY key ON

SPPD3

SPPD4

STRC
Document transport clutch

SPPD1
Document transport sensor 1

SPPD2
Document transport sensor 2

SRRC
Resist clutch

SPOD
Document exit sensor

Scanner scan 

CIS scan

Document transport sensor 3

Document transport sensor 4

Resist brake clutch

SRRBC

Document transport brake clutch

STRBC

ON when scan ready OK (cycle time 923ms)
OFF after 18mm (50ms) of SPPD3 off

Transport speed 360mm/s

Letter (216mm) 65 sheets (Single surface)

STRRBC
Document transport resist brake clutch

Document transport resist clutch

STRRC

ON simultaneously with print start
OFF when the last paper SPOD off

First sheet ON simultaneously with the second ON of SPFC (paper feed CL)
OFF after 18mm (50ms) from SPPF1 off
Second and the following sheets ON simultaneously with SRRC on
OFF after 18mm (50ms) from SPPD1 off

First sheet: Paper feed start after booting the motor (Clutch ON)
Off at 24mm (67ms) from SPPD1 on (SIM adjustment)
ON again after 30ms from OFF, and OFF after 60mm (167ms)
Second and the following sheets: The 2nd sheet start simultaneously with SPPD1 off (Clutch ON)
OFF at 24mm (67ms) from SPPD1 on (SIM adjustment)
ON simultaneously with SRRC on, and OFF after 60mm (167ms)

First sheet ON simultaneously with SPPD1 on
Second and the following sheets OFF before10ms of STRRC on
ON after 5ms of STRRC off
First sheet ON simultaneously with STRRC
and OFF simultaneously with SPPD3 on
ON before 36ms (SIM adjustment) of SRRC on
ON after 5ms of STRC off
OFF before 10ms of STRC on

ON simultaneously with SPPD3 on
OFF before 10ms of SRRC on