Message says "release the scanner lock switch and turn the power off and back on" Where is the switch?

The scanner lock on the MP980 is on left hand side of the scanner unit. It's closer to the hinge of the document cover and almost centered between the scanner glass and the edge of the printer. If you lifted the entire scanner unit, you won't see the switch. You should be able to push the switch towards the open lock symbol with your finger or thumb. The Getting Started guide has a pretty good picture of where the switch is in Step One. The guide is available on the product page, http://www.usa.canon.com/cusa/support/consumer/printers_multifunction/pixma_mp_series/pixma_mp980#BrochuresAndManuals , in the Brochures & Manuals section. The current link to the Getting Started Guide is http://gdlp01.c-wss.com/gds/2/0300001552/01/MP980_GS_EN-US_V3.pdf . After moving the switch, turn off the all-in-one. Then unplug the power cord to clear the error message from the printer's memory. After a few minutes, plug the power cord back in and turn on the printer.

If the error persists and the scanner is unlocked, the scanner mechanism may be damaged. If that's the case, your MP980 needs service. If the unit is under warranty, contact Canon. (If it isn't under warranty, you'll need to decide if the unit is worth the shipping and handling fees and the minimum $50 or so charge just to determine the problem at a service center. (That fee will be applied to the cost of fixing the printer, if you decide to have the technician continue to work on the unit.)

I hope this helps.

Cindy Wells

All scanners come with the scanning head locked to prevent damage to it during shipping. On the back of the scanner, where the power cord and wires connect, there will be a sliding switch, sometimes a turning type lock, with two positions, one with the icon of a closed [so locked] padlock and the other with the icon of a open [so unlocked] padlock. Every scanner I have bought describes this lock in the setup manual.

This took me forever to find. Please let me know if it works.
http://support-th.canon-asia.com/contents/TH/EN/8000675301.html

It means scanner locked

action:

Slide the lever to lock the scanner in the open position, turn off and turn MFP

Issue: ERROR LCD: Release the scanner lock switch and turn the power off and back on.
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Solution: Unlock the scanner lock switch

The scanner must be unlocked before turning the unit on.

Turn off the power.

Lift the document cover.

The scanner lock switch is on the left hand side of the underside of the document cover.

Slide the scanner lock switch to the release mark (an open padlock icon).

Lock the switch before transporting.

Close the document cover.

Turn the machine on.

If machine still is not working repeat the power off / on cycle waiting 5 seconds in between.

This seems to be a pretty universal thing for Cannon scanners
http://support-th.canon-asia.com/contents/TH/EN/8000675301.html

See this link. If you search at Fixya, you often will find the answer as it may have been asked before.

Make sure to unlock the scanner switch before turning the machine on. Then turn the on/off switch on, off for 5 seconds, then back on.

When [L1-00] appears, the scan head
locking switch is locked. Turn off the
power, release the scan head locking
switch, WAIT 10 SECONDS and turn the power back on.

The scanner lock is locked pls unlock it dude...