How to Fix Blurry or Double Printing on an Epson SureColor F170 After Replacing the CR Scale Strip

Question:
My Epson SureColor F170 Sublimation Printer started printing double images that looked extremely blurry. I found information online suggesting that a faulty CR Scale Strip could be the cause, so I ordered a replacement from BCH Technologies in May 2025. After installing the new strip, things got worse - now the printer displays a paper jam error even though there isn't one. I noticed that the replacement strip had scratches when I received it. I'm not seeking a refund, but I would greatly appreciate some advice on what to do. My printer's warranty expired in April 2025, and this issue is creating a major setback for my business.

Answer:

Based on your description and the photos you provided, your printer's double or blurry images indicate a problem with the carriage alignment or timing synchronization, rather than the printhead itself. Here's a detailed explanation and steps to address the issue:

1. Check for Bi-Directional Printing Issues

In most cases, double printing happens when bi-directional printing (also known as "high-speed" or "fast" mode) is turned on. When this mode is active, the printer prints in both directions - left-to-right and right-to-left. However, if there's any misalignment or timing drift, the reverse pass won't line up correctly, creating a double or shadowed image.

• To test this, go to your printer settings on your computer and disable bi-directional printing.

• Then print a test image. If the output becomes clear, the issue is alignment-related rather than a hardware defect.

2. Inspect and Clean the CR Scale Strip

The CR (Carriage Return) Scale Strip-also known as the timing strip-is the thin transparent strip behind the printhead that helps the printer determine exact horizontal position. If this strip is dirty, scratched, or loose, it can cause misreads and result in erratic head movement, blurry lines, or false error messages such as a paper jam (even when no paper is stuck).

• Remove the CR Scale Strip carefully and clean it gently with isopropyl alcohol and a lint-free cloth.

• Avoid touching the strip with your fingers, as oils can affect its transparency and sensor readings.

• Reinstall it tightly - there should be no slack or bend. Ensure both ends are properly seated in their slots.

If the strip you received has visible scratches, that could also cause the sensor to misread position marks. While minor scratches often won't stop operation, deep or multiple scratches across the coded marks can trigger CR Encoder Sensor Errors or Paper Jam Errors (e.g., Error Code 0xEA or 0xF1 on Epson models).

3. Verify the Encoder Sensor Alignment

The CR Encoder Sensor, which reads the timing marks on the scale strip, might be misaligned or contaminated.

• Locate the small black sensor module near the printhead carriage and make sure it is securely mounted.

• Use compressed air or a soft brush to clear any dust buildup.

• A misaligned sensor can cause the printer to misread the scale, leading to the "paper jam" or "carriage jam" messages even when the path is clear.

4. Mechanical Alignment and Tightness

Ensure that the CR Scale Strip is tight and parallel to the carriage path. If the strip is loose or twisted, the printhead movement readings will be inaccurate. Check both ends where the strip mounts into small slots or tabs.

If none of these steps resolve the problem, the issue could be in the mainboard calibration or encoder signal interpretation, which typically requires in-person diagnostics.

Addressing printer issues can be a complicated affair due to the hands-on nature of the problems. Therefore, we're unable to provide remote troubleshooting or detailed repair support. We do, however, offer in-person evaluation and repair through our local diagnostic facility (https://bchtechnologies.com/printer-repair-service). Due to high demand, we operate on a first-come, first-served basis, so it might take a few weeks before we can examine your printer once it's dropped off. Our services cover both full printer repairs and part-specific diagnostics. While our rates may not be the most budget-friendly, we encourage customers to explore self-help solutions as well-such as researching through YouTube (https://youtube.com/@bchtechnologies) or using the search icon on our channel's homepage to find specific repair tutorials.

Thank you once again for reaching out to us and for your patience. We greatly appreciate your trust in BCH Technologies, and we'll continue doing our best to help you and other printer users get back to smooth, trouble-free printing.