Question: Hi Kevin, I'm facing a persistent "Cover is open" error with my Canon MX350 printer despite trying to locate the problem. I suspect a sensor issue but am unable to pinpoint whether it's a micro switch or optical sensor. Can you help me identify its location to avoid disposing of the printer?

Answer: Thank you for reaching out with your query about your Canon MX350 printer. We at BCH Technologies truly appreciate your involvement and rely on your feedback to enhance our technical assistance. Your engagement with our YouTube channel (BCH Technologies) is especially valuable.

For the "Cover is open" error you're encountering, it sounds like you're on the right track by considering a sensor issue. This error generally indicates that the printer's internal sensor is not detecting the closure of the scanning unit or document cover correctly. In the Canon MX350, this is typically related to the Scanning Unit Detection Button. This button is crucial as it locks the scanning unit while the document cover is open. It's designed to be pressed down when the document cover is closed, allowing you to open the scanning unit cover safely.

Since you've already dismantled the printer, look for a small button or lever located near the edge of the scanning unit.  The sensor is a micro switch, which physically clicks when activated.

Check if it's stuck or if there's any debris causing it not to engage properly when the cover is closed.

Addressing printer issues can indeed be intricate due to the tactile nature of such tasks. For example, addressing a simple clog might require a specific unclogging procedure. Moreover, if the printer has been inactive for a long period, a thorough maintenance of the ink system might be necessary. Issues like "paper jam" could have numerous potential causes, and it's somewhat of an inside joke in offices how varied the causes can be. Unfortunately, we're unable to offer remote troubleshooting, suggestions, or support for printer repairs. We provide an in-person evaluation and repair service through our local diagnostic facility (BCH Printer Repair Service). Due to high demand, services are provided on a first-come, first-served basis, and it may take some time to schedule your printer for an evaluation, whether you choose to drop it off or mail it in. While our rates may not be the lowest, we recommend trying to resolve the issue yourself through online resources. Begin by visiting our YouTube channel's homepage and using the search function to find specific videos or explore similar content from other creators.

Thank you once again for contacting BCH Technologies, and we hope this guidance assists you in resolving the "Cover is open" error on your Canon MX350 printer. If you have any more questions or need further assistance, please don't hesitate to reach out.