Canon FaxPhone L90, Service Manual

Page: 65 / 128

Chapter 7
7-1
7.1 Power Supply
7.1.1 Protection Function
7.1.1.1 Protective Mechanisms
0018-4917
The protective mechanisms include an overcurrent protective circuit that
uses a fuse. If short circuit or the like occurs because of some fault and, as a
result, an overcurrent flows, the fuses will melt to cut off the power to the
power supply circuit.
The power supply circuit is equipped with 2 fuses (FU1, FU2); in the event
an overcurrent flows into the AC line, either of these fuses will melt to cut
out the current.
7.1.2 Backup Battery
7.1.2.1 Battery-backed up Data
0018-4918
The machine is equipped with a battery used to back up the clock IC.
The lithium battery (BT1) on the SCNT starts to supply power to the clock
IC when the jumper pin (CJ2) is shorted by a jumper plug.
The machine does not have a mechanism to back up image data. As such,
loss of power (e.g., power outage or disconnected power cord) will lead to
loss of images.
7.2 Parts Replacement Procedure
7.2.1 Front Cover
7.2.1.1 Preparation for Detaching the Front Cover
0018-3823
1) Remove the document feed tray and the paper tray cover.
(page 7-2)
Ref-
erence[Removing the Document Feed Tray and the Paper Tray Cover]
2) Detach the right cover.
(page 7-2)
Reference[Detaching the Right Cov-
er]
3) Detach the left cover.
(page 7-2)
Reference[Detaching the Left Cover]
7.2.1.2 Detaching the Front Cover
0018-3809
1) Disengage the 2 claws [1] in the arrow [A] direction.
2) Disengage the 2 claws [2] in the arrow [A] direction.
3) Insert a screwdriver etc into the indicated hole [3] by approx 30 mm in the
arrow [A] direction to disengage the claw [4].
4) Detach the front cover [5] in the arrow [B] direction.
F-7-1
7.2.2 Rear Cover
7.2.2.1 Preparation for Detaching the Rear Cover
0018-3915
1) Remove the document feed tray and the paper tray cover.
(page 7-2)
Ref-
erence[Removing the Document Feed Tray and the Paper Tray Cover]
2) Detach the right cover.
(page 7-2)
Reference[Detaching the Right Cov-
er]
3) Detach the left cover.
(page 7-2)
Reference[Detaching the Left Cover]
7.2.2.2 Detaching the Rear Cover
0018-3912
1) Remove 1 screw [1].
2) Free the grounding cable [2] from the cable guide [3] on the rear cover.
F-7-2
[2]
[1]
[2]
[A]
[A]
[A]
[B]
[5]
[2]
[3]
[4]
[1]
[2]
[A]
[A]
[3]
[2]
[1]