Epson ET-8550 Paper Jam Fix: Why Your Printer Feeds Half a Page and Jams Under the Print Head

Question:

My Epson ET-8550 pulls in about half a page and then jams whenever the print head moves over the sheet. I already cleaned the PW sensor, reinstalled it, and even replaced it with a new one. The printer sometimes works briefly but then fails again. I've cleaned the guides thoroughly. What else could be causing the issue, especially since the print head seems to push the paper backward and cause the jam?

Answer: 

You've already taken the right first steps: cleaning the PW sensor, reinstalling it, and even replacing it. Since the problem persists, it's important to look beyond the sensor itself and into the conditions the sensor needs in order to work.

Below is a detailed breakdown of what typically causes this exact symptom on the Epson ET-8550-paper feeding halfway and then jamming as soon as the print head tries to pass over it.

1. The Paper Type May Be Invisible to the Printer's Sensors

This is a common issue we see with the ET-8550.

The PW (Paper Width) sensor and other feed sensors rely on light reflection. Transparent or semi-transparent media often fails to reflect enough light back to the sensor. When this happens, the printer doesn't properly detect the page and may:

• incorrectly calibrate the feed
• fail to recognize the sheet position
• push the paper backward when the print head moves
• trigger a jam despite no physical obstruction

This often appears to users as a jam under the print head even though the mechanical parts are clean and the sensors are new.

If you are printing on transparent film or glossy film (DTF film, OHP-style sheets, clear media, etc.), the printer often cannot detect it reliably. A working PW sensor cannot fix this.

Solution:

Test with plain paper first. If plain paper feeds normally without jamming, the issue is confirmed: the printer cannot reliably read transparent media.

To print specialty media, try:

• Double-sided matte film (these reflect light better and are detected more consistently)
• Paper-based transfer sheets now available on the market
• Matte-coated opaque sheets made for inkjet photo output

These materials provide enough reflectivity for the ET-8550 sensors to function properly.

2. The Print Head Pushing the Page Backwards Is a Sensor Detection Failure

When the print head pushes the sheet backward instead of gliding over it, this typically indicates the printer is not tracking the paper edge correctly. This is nearly always related to:

• Poor reflectivity (clear film)
• Warped, curled, or overly slick sheets
• Media thickness outside Epson's specification
• Incorrect driver media type forcing pressure misalignment

Even when the PW sensor is functioning, it depends entirely on the media surface returning enough light for the printer to confirm the sheet's position.

3. Driver Settings Can Influence Feed Pressure and Timing

The "Media Type" setting in the Epson driver adjusts:

• feed roller torque
• pinch roller pressure
• timing for the paper advance steps

If "Premium Presentation Matte," "Glossy," or similar settings are used on incompatible media, the timing may cause a misfeed resulting in a jam under the head.

Solution:

When testing, set:

• Media Type: Plain Paper
• Color Management: Off / No Color Adjustment (for testing feed only)

This ensures the printer uses baseline feed pressure and timing.

4. Confirm That the PW Sensor Pathway Is Not Blocked

Even with a new sensor installed, pay attention to:

• debris under the sensor bracket
• cloudy or damaged sensor window
• misalignment in the sensor mount
• curled paper edges lifting as the head passes

These physical issues can cause intermittent paper detection failure.

5. The Sensor Passes Testing, but the Media Still Fails

This is the most important takeaway:

A functioning sensor cannot compensate for media that is outside the printer's detectable range.

This is why your cleaned and replaced PW sensor works sometimes and fails other times-the problem is not the sensor, but the media's interaction with it.

Addressing printer issues can be complex because many problems require hands-on inspection of the machine and the media used. For this reason, we're unable to provide remote troubleshooting, repair guidance, or individual technical diagnosis. We do offer in-person evaluation and repair at our local diagnostic facility, BCH Technologies Printer Repair Service (https://bchtechnologies.com/printer-repair-service). Due to high demand, intake works on a first-come, first-served basis and scheduling may take a few weeks. Our services cover complete printer repairs or specific component repair, with clear drop-off procedures. That said, we understand that repair costs are not always ideal, so we strongly encourage self-help through online resources. You can start by browsing tutorials on YouTube or using the search function on our channel homepage at BCH Technologies on YouTube (https://youtube.com/@bchtechnologies). The search icon near the "About" tab helps you locate videos quickly by keyword. With nine years of uploads and many daily inquiries, searching directly often leads to faster results-and YouTube may even recommend helpful videos from other creators.

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