Epson ET-8550 Printer Screeching Noise: Reasons and Solutions

Customer Inquiry
I have an Epson ET-8550 printer, and when I print, it makes a screeching noise. I have also watched your videos on YouTube but haven't found a way to fix this. I'm not sure if there's anything you can do to help, but I'm hoping that you can recommend something or advise the best way to fix this situation. 
 
Answer:
Thanks for reaching out, and I'm sorry I didn't respond sooner. I know how frustrating printer problems like this can be, and I appreciate your patience. We want to thank you from the bottom of our hearts. You all are amazing with your love for BCH Technologies, with special reference to BCH Technologies' YouTube channel (https://youtube.com/@bchtechnologies) and other social media platforms. Thanks for reading and engaging with us; your feedback helps us fine-tune our content and expand our technical expertise.
 
Diagnosing the Hear That Screeching Sound
A few common causes of the grinding noise from your Epson ET-8550 printer generally relate to the mechanical parts of the printer. Here are the most common culprits based on your description:
 

• CR Encoder Interference: The CR encoder (Carriage Return Encoder) is a strip or disk that helps track the movement of the printhead carriage. If the encoder strip is damaged or interfered with, the printhead can swing from side to side on an inconsistent valve or resist when it reaches the end of its travel, often making a screeching sound. Over the years, the strip can get dirty and/or out of alignment, impacting the carriage's smooth movement.
• APG Unit Interfere: The APG (Auto Paper Guide) unit is a key unit in the printer as it is responsible for guiding the paper during printing. If the APG unit is out of adjustment or there is an obstruction, it will touch other moving parts, such as the printhead carriage. This can create friction or resistance, which is what the screeching noise you hear is a sign of.
• APG Lock: This mechanism holds the paper guide, which could also cause some unwanted noise when pulling out a paper guide that isn't working correctly. When the lock is stuck, or the guide is not correctly locked, the movement of parts will produce screeching sounds, which can also be heard during the printer's operation.
• Page width sensor not detecting( Page width sensor problems): The page width sensor senses the paper size loaded in a printer. If this sensor isn't working or aligned correctly or covered, it can cause the printer's carriage to resist or drive incorrectly, causing the noise you're hearing. The exact position of the sensor can vary between printer models, but it is often situated around the paper path. Any debris or dust buildup in that area could affect the sensor's ability to read the page size properly.

Recommended Solutions

• Clean the CR Encoder Strip First, check if the CR encoder strip is dirty or damaged. If it looks dirty, it can be wiped down with a soft, lint-free cloth moistened with water or a mild cleaning solution. During the cleaning process, avoid damaging the strip itself or any connectors. If you see any rips or major wear on the encoder strip, you may have to replace that as well.
• APG Unit and Lock Mechanism Check: APG units and physical APG locks should be free of obstruction or misalignment. If the APG lock does not engage, the carriage may be stuck; gently release the APG lock and ensure that it's not harnessing the carriage's movement. Check the whole route that the paper guide follows through the printer and see if anything is blocking it. If the unit seems to be defective, you will have to replace it or make adjustments.
• Examine Page Width Sensor: The page width sensor can become dusty or covered with ink residue, leading to problems. Use a soft cloth or cotton swab dampened with water to clean the sensor. Verify that there is no physical damage to the sensor and that the alignment is correct. If the sensor continues to fail even after cleaning, it may need to be replaced.
• For moving parts: If you hear a screeching noise when driving, try lubricating the carriage rails or any other parts in the printer. Drops of printer-safe lubricant or grease are applied to the rails to help the system move smoothly. Be careful not to use too much lubrication because too much grease will attract dust and create problems.
• Inspect for Other Mechanical Problems: If the noise persists, consider checking other mechanical elements, like the drive gears or the belts, to confirm that they function correctly. Old or loose gears and belts can also create friction and make screeching noises.

General Advice
Addressing the printer problem you have may take a little care with the moving part of the printer. We cannot offer remote troubleshooting or specific printer repairs. However, we can evaluate the printer in person or repair it at our local diagnostic (https://bchtechnologies.com/printer-repair-service) on a first come, first served basis, and it may take a few weeks to inspect and fix the printer if we are currently overwhelmed with orders. Finally, check out our YouTube channel (https://youtube.com/@bchtechnologies) for other troubleshooting videos. Our channel has numerous helpful tutorials and guides for different Epson printers. Search our channel's homepage for videos specific to your issue. Remember, I get dozens of questions daily on any number of topics, so the YouTube search tool is often the fastest way to find the right video.
 
Again, thank you for contacting us, and I hope these tips help eliminate the screeching sound. Please don't hesitate to contact us again with further questions or updates.