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Canon LBP 2900 Printer Scanner Unit Error Fixed

By on June 3, 2022
Canon LBP 2900 Printer Scanner Unit Error Fixed

canon laser printer repair

Received Laser printer for repair, it is giving “Scanner Unit error” on the screen of the computer while giving printing command.

how to fix a broken canon laser printer

So this error is lead to suspect faulty area is…

1) Flexible Flat Cables OF ECU.

2) Power Board which gives power to ECU

3) ECU Board.

4) Scanner Unit Itself.

canon laser scanner unit repair

For detail photographs of the parts please refer to this link because Model is same as the printer I received for the repair. Opened the printer for visual inspection; here I found suspected parts are ECU Unit Cables.

Both cables are badly oxidized and copper trace contacts are not visible.

fpc printer cable replace

Cleaned Both the Cables using ink eraser rubber & then wiped using IPA…

cleaning scanner using ipa

After cleaning process I reassembled the printer for testing ……..

I took few printout & it works without any error.

yogesh panchal

This article was prepared for you by Yogesh Panchal who works as a Computer Hardware Engineer in Mumbai India.

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Note: You can check his previous repair articles on No Power In Calculator Repaired



  1. Parasuraman S

    June 3, 2022 at 9:25 pm

    One need to be cautions in using liquid or oil in cleaning these types of cables. The blue tip holder would come off and afterwards it will be very difficult to insert it. It is not easy to fix it back. Many thanks for sharing!

  2. Babu M S

    June 3, 2022 at 10:33 pm

    Very good repair work.Thanks for sharing.

  3. Yogesh Panchal

    June 3, 2022 at 10:55 pm

    Absolutely Right,Never ever try to stick it using instant glue if glue is spread on open trace contact you have to buy a new cable.

  4. Albert van Bemmelen

    June 3, 2022 at 11:11 pm

    These flex flatcables often cause many problems, especially those connected onto displays and special foil keyboards. But I guess that the badly oxidized cables in this repair tell that there is more going on that caused this which normally never should happen.

  5. Imoudu.O

    June 4, 2022 at 1:50 am

    I have not try my hand on a printer before,but this is a hint for me.Thanks for sharing.

  6. Waleed Rishmawi

    June 5, 2022 at 7:35 pm

    These cables are constant fault that see in many devices. Last time I had an issue with one of the flex cables in a dental machine that took me a while to get. Have a blessed day and thanks for sharing


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