Epson WF-7510 Error After Printhead Replacement- Causes and Solutions

Question:
I’m servicing an Epson WF-7510 and have replaced the printhead. However, after reassembly, the printer only shows a general “printer error” screen instructing me to turn off and restart, without displaying a specific error code. The printhead assembly never initializes, and the green lights flash. I’ve experienced this before after cleaning or replacing a printhead. What could be causing this, and how can it be fixed?

1. General “Printer Error” Without a Code

On many Epson models, especially the WF-7510 and WF-7610 series, a “printer error” without a numerical code usually indicates a hardware initialization failure. This is often triggered before the printer even reaches its self-diagnostic stage.

When you see the flashing green lights and no head movement, the printer’s logic board is stopping the startup process to prevent potential damage.

2. Common Causes After Printhead Replacement

a. Ribbon Cable Misalignment or Loose Connection

• The flat flex cables (FFC) that connect the printhead to the mainboard are very sensitive. If a cable isn’t seated perfectly, the printer can’t detect the head, leading to a “printer error” halt.

• Even a slight misalignment of one contact pad can cause a failure to initialize.

• Solution: Remove and carefully reinsert each cable, ensuring it is fully seated and locked in its connector. Check for bent pins or contamination on the contacts.

b. Damaged Printhead Data Lines

• During cleaning or replacement, static discharge or mishandling can damage the tiny signal lines in the printhead.

• The printer’s firmware will block operation if it detects abnormal resistance in the head’s circuitry.

• Solution: If reseating doesn’t help, try the original head (if available) to see if the error changes. This can confirm if the replacement head is faulty.

c. Carriage Lock or Mechanical Resistance

• If the carriage lock is not released or there’s debris in the carriage rail, the head assembly won’t move during startup.

• Solution: Inspect the carriage movement manually (with the printer unplugged). It should slide freely across the rail.

d. Incorrect Model Head Installed

• The WF-7510 and WF-7610 use similar but not identical printheads. Installing a head from a different Epson model may cause an instant error because the firmware rejects the ID signal.

3. Advanced Causes (Mainboard or Power Issues)

Mainboard Communication Failure

• If all cables and the head are good, the mainboard may have a damaged printhead driver IC or MOSFET from a prior head short.

• This type of repair involves board-level diagnostics and replacement components—best handled by an experienced technician.

Power Supply Voltage Drops

• Low voltage from the PSU can cause the carriage motor or head to fail its startup check.

• This is rare but can be tested with a multimeter to confirm stable 24V and 42V rails under load.

Addressing printer issues can be a complicated affair due to the hands-on nature of the problems. As such, we can’t provide remote troubleshooting or walk-throughs for physical repairs. We do offer in-person evaluation and repair services (https://bchtechnologies.com/printer-repair-service) at our local diagnostic facility. Due to high demand, repairs are handled on a first-come, first-served basis, and there may be a wait of several weeks before we can inspect your printer. We can repair entire printers or specific parts, but our rates may not be the lowest. For this reason, we recommend self-help where possible, starting with searching our YouTube channel (https://youtube.com/@bchtechnologies). Use the search icon next to “About” in our menu bar to locate videos quickly. With hundreds of uploads over the last nine years, it’s the most efficient way to find guidance, and YouTube may also suggest other helpful videos from different creators.

Thanks again for your patience and for reaching out to us—we truly value your continued support.