Epson 7890 A139 Error: How to Fix Printhead Connection and Fuse Issues

Question:
My Epson Stylus Pro 7890 is showing an A139 error (also referred to as 1A39) right before printing. What does this error mean, and how can I fix it?

Answer:

Now, let's discuss the Epson 7890 A139 (1A39) error. This code generally indicates a problem with the printhead or its related electrical connections. It's often triggered by one or more of the following issues:

1. Loose or Damaged Ribbon Cable - Over time, the ribbon cables connecting the printhead to the mainboard can become loose or oxidized. Carefully inspect the ribbon cables for any visible damage, corrosion, or loose connections. Reseat them securely and ensure they are fully inserted into the connectors.

2. Blown Fuse on the Mainboard (F1 or F2) - The fuses labeled F1 and F2 on Epson printers like the ET-8550 or 7890 protect critical circuits that power the printhead. A power surge or short circuit can cause these fuses to blow, resulting in error 1A39. You can check the fuses using a multimeter for continuity. If either fuse is open, it must be replaced with a fuse of the exact same rating. Be cautious-replacing fuses improperly can lead to further board damage.

3. Dirty Encoder Strip - The clear plastic encoder strip behind the carriage tells the printer where the printhead is positioned. If it's smudged or covered in ink mist, the printer can misread its position and throw this error. Clean it gently with a lint-free cloth and isopropyl alcohol (90% or higher).

4. Printhead Failure - If the ribbon cables and fuses are intact but the error persists, the printhead itself might be shorted or damaged. This is especially common if ink or moisture has entered the printhead circuitry. Unfortunately, a defective printhead usually requires replacement.

5. Mainboard Damage - In some rare cases, the A139 error stems from mainboard failure, particularly if the printer experienced a power surge or was serviced improperly. If you suspect this, professional inspection is advised.

If you're comfortable working with printer electronics, you can inspect the F1 and F2 fuses on the mainboard using a magnifier and multimeter. For visual guidance, you may want to review repair tutorials such as those on our BCH Technologies YouTube channel (https://youtube.com/@bchtechnologies), where we show step-by-step diagnostics for similar models.

Addressing printer issues can be a complicated affair due to the hands-on nature of the problems. Therefore, we're not able to provide remote troubleshooting or direct repair support. However, we do offer in-person evaluation and repair through our local diagnostic facility at BCH Technologies Printer Repair Service (https://bchtechnologies.com/printer-repair-service). Because of high demand, services are handled on a first-come, first-served basis, and it may take several weeks before drop-off. Our services cover both full-printer repairs and component-level fixes. We understand our rates may not be the most economical, so we encourage self-help by exploring resources on YouTube - especially by using the search function on our channel homepage (https://youtube.com/@bchtechnologies).

Thank you again for your question and for being part of our community. Your continued engagement helps us refine our content and share deeper technical insights to assist more printer users like you.