Epson Stylus Pro 7890 Fatal Error 1A39: Causes and Fixes

Question:

I had a printer (Epson Stylus Pro 7890(Model K161A)) with Fatal Error Code (1A39). They said it was the motherboard, so we ordered one and installed it. After replacing the board, the error still came up. We are now being told that the issue may have to do with the printhead. What would be the actual cause, and what action should we take?

Answer:

What is Fatal Error Code 1A39?

The 1A39 error on the Epson Stylus Pro 7890 usually means a head error, or that the drive circuit for that printhead is faulty. This can occur due to:

• A misaligned or improperly connected Head FFC (Flat Flexible Cable)
• The printhead short-circuited
• A blown fuse on the mainboard

The way you would use all that information here is that since the motherboard has already been replaced and the error still comes up, it is likely that the issue is the printhead itself or the FFC to the new motherboard.

Troubleshooting Steps

Verify the Printhead FFC Connection

• Disassemble the printhead and check closely the Head FFC cable that connects it with the Sub Board Assy.
• Tighten it up if the cable is not bad or half disconnected.
• Replace the FFC cable with a new one if any terminals are damaged/burnt.

Test the Printhead for a Short Circuit

A broken printhead can short circuit and blow the fuse on the motherboard. What this means is, even replacing the motherboard, the replacement could die almost instantly if the printhead is the issue. Here’s what I recommend:

• Now remove the printhead from your printer.
• Check for burn marks, corrosion, or damage where the connectors make contact.
• Ensure a solid connection clean the connectors with a lint-free cloth and isopropyl alcohol.

If the printhead is already shorted, the only solution is to replace it.

Inspect the Mainboard Fuse

Since you purchased a new mainboard, it is important to ensure that the fuse has not blown due to a faulty print head.

• Pull out the mainboard and check near the printhead connector for fuses.
• If the printhead is shorted, replacing the motherboard alone will not work—you'll have to replace the faulty printhead first.

Recommended Fix

If you have already replaced the mainboard, I highly recommend replacing the printhead before replacing any more motherboards. Otherwise, a shorted printhead could continue to short out and ruin new mainboards in an endless cycle of failed components and wasted money.

By the way, we repair mainboards at BCH Technologies. If the first motherboard is still functional, we can troubleshoot and fix it without buying another one.

Important Service Note

Printer problems like these can be intricate and involve some hands-on tinkering. We try to provide as much advice as we can, but if there is a problem, we cannot provide remote troubleshooting or repair support. We do offer local walk-in diagnostic and repair service at our repair shop (https://bchtechnologies.com/printer-repair-service), but please note that because we are in high demand, that service is first-in-first-out and backed up as well, and wait times can be significant.

For full printers or specific parts, we provide direct instructions on how to continue. Our repair fees may not always be the cheapest, so we suggest helping yourself using the internet.

For diagnostic videos, head to our YouTube channel (https://youtube.com/@bchtechnologies) where you can search for related repair guides using the search icon next to About. With more than nine years of video, searching YouTube is frequently the quickest way to find help, and it might also suggest other helpful repair videos.

Many thanks for getting in touch! Thank you for your continued support, and we hope this gets you through the repair process. Article by: [Your Name] If you have more follow-up questions, please visit our resources section or contact us.