Canon LBP7100Cn User Manual page 455

<How to disconnect the cable or cord>
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USB cable
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LAN cable
Power cord
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Whether the cable is connected or not varies depending on your environment.
4
Contact your local authorized Canon dealer to request service.
When contacting your Canon dealer, please report also the error code which you noted down in Step 2.
If you are not sure what the problem is, contact your local authorized Canon dealer.
(2) Turn the computer off.
(3) Disconnect the cable from the printer.
(4) Disconnect the cable from the printer.
(5) Disconnect the power plug from the AC power outlet.
(6) Disconnect the cable from the printer.