Locating and Replacing the Paper Eject Sensor on Epson ET-8550

Question:
I'm having issues with my Epson ET-8550 and believe the paper eject sensor may be dirty or faulty. I saw that BCH Technologies sells replacement sensors, but I can't figure out where this sensor is located. I've seen your video on replacing the paper width sensor, which was helpful, but I can't find similar information on the paper eject sensor. I heard it's behind or below the mid-paper guide, but I'm not sure where exactly that is. Can you help me locate it on the ET-8550?

Answer:

1. Location of the Paper Eject Sensor

• The paper eject sensor is located underneath the carriage rail, positioned around the center area.

• Look for the black paper guide plates with springs-the sensor is situated in the middle of these guides.

• Unlike the paper width sensor (which is easier to access near the paper path), the eject sensor is somewhat hidden and requires carefully moving parts out of the way to reach it.

2. Function of the Paper Eject Sensor

• This sensor detects whether paper is exiting correctly after a print job.

• If dirty or faulty, the printer may throw paper jam errors even when no paper is stuck, or it may stop mid-job.

3. Cleaning Before Replacing

• Sometimes, the sensor isn't broken but just dirty with ink mist or dust.

• Use a can of compressed air or a lint-free cloth with isopropyl alcohol to gently clean around the guide plates.

• Be cautious not to bend the sensor lever or misalign the spring mechanism.

4. Replacement Considerations

• If cleaning doesn't fix the problem, then replacing the sensor is the next step.

• BCH sells compatible sensors, but installation requires partially disassembling the mid-paper guide assembly.

• If you attempt replacement yourself, take photos during disassembly so you can track spring positions and plate alignments.

5. Common Symptoms of a Bad Paper Eject Sensor

• Printer constantly reports a paper jam when the path is clear.

• Paper feeds and prints but won't eject fully, then throws an error.

• Printer stops mid-job with a false jam warning.

Addressing hardware issues like sensor replacement can be a complicated affair due to the hands-on disassembly required. That's why we aren't able to provide remote troubleshooting or direct support for this type of repair. However, we do offer an in-person evaluation and repair service (https://bchtechnologies.com/printer-repair-service). This operates on a first-come, first-served basis, and due to high demand, it may take several weeks before your printer can be processed. We repair both full printers and specific parts, but we acknowledge that our rates may not always be the most economical. For many customers, the fastest path is self-help, and a great place to begin is our YouTube channel (https://youtube.com/@bchtechnologies). Use the search icon next to the "About" tab to look up videos on sensor cleaning, ET-8550 troubleshooting, and paper path diagnostics.

Thank you again for your question and for supporting BCH Technologies. Your persistence in solving these issues helps us continue creating guides and resources that support the wider printer repair community.