Epson Error 031006 After Fuse Replacement: Can One Blown Fuse Cause a No-Print Head?

Question:
I bought a pack of fuses from you to replace F1, F2, and B15. I removed the motherboard following your instructions and checked continuity. F1 and B15 have continuity, but F2 does not and seems blown.
Can I get error 031006 if only one of the two fuses is dead? Before the error, I noticed the printhead wasn't printing anything. I'm going to replace the fuse and test again, but should I also worry that the two silver MOSFETs are bad?

Answer:

Can error 031006 happen with only one blown fuse?

Yes-it can. In many Epson mainboards, the printhead drive circuitry is split into multiple channels/rails. Depending on the model and board layout, F1, F2, and B15 may protect different sections of the printhead power/drive path. If only F2 is open (blown) while F1 and B15 still read continuity, the printer can still detect a head-drive abnormality and throw 031006-especially if the channel protected by F2 is required for firing certain nozzle groups.

That said, continuity alone doesn't guarantee the circuit is healthy under load. A fuse can read "good" but still have high resistance, poor solder joints, or downstream shorts that only show up when power is applied.

Why did the printhead stop printing before the error appeared?

That sequence is common when something in the head-drive path is failing:

• A fuse partially failing or going open can cause intermittent or total loss of firing.

• A MOSFET short (or driver failure) can cause overcurrent that blows a fuse. Sometimes the fuse fails first; other times the MOSFET fails first and takes the fuse out afterward.

• A shorted printhead / head cable / connector contamination can overload the head drive line and eventually trigger protection and an error like 031006.

So the "no print" symptom doesn't automatically mean the head is dead-but it does strongly suggest the head-drive circuit wasn't delivering proper firing energy.

Should you replace the fuse first, or assume the MOSFETs are dead too?

Your plan-replace the blown fuse and test-is reasonable, but with one big caution:

If a MOSFET (or the load) is shorted and you simply replace the fuse, the new fuse may blow immediately (or worse, additional components may be damaged). So the safer order is:

1. Identify whether there's a short on the protected line(s) before powering on.

2. Then replace the fuse and test.

Could it be "just one fuse," or are MOSFETs often involved?

It could be any of the following (and I'm aligning this with your own assessment, because it's exactly the right way to think about it):

• Only one fuse dead (e.g., F2 blown) and the MOSFETs are still okay.

• Both fuses dead (depending on the board's head-drive protection design).

• Fuse + MOSFET failure on one channel.

• Fuse + MOSFET failure on both channels.

And yes-there are usually multiple MOSFETs involved (commonly two per channel or similar arrangements), so it's not unusual for one set to fail while the others survive.

How to check if the "two silver MOSFETs" are likely bad (before powering up)

Without knowing your exact Epson model/board revision, here are practical checks that typically apply:

1) Quick short check around the blown fuse's output

• With power off and board removed (or at least isolated), measure resistance from the load side of F2 to ground.

• If it reads very low resistance (near short), that's a strong indicator something downstream-often a MOSFET or the head/cable-is shorted.

2) MOSFET basic test (common failure mode: Drain-to-Source short)

Many head-driver MOSFET failures show up as a short between major terminals.

• If you have diode/ohms mode, compare the suspect MOSFET readings to the same MOSFET positions on the "healthy" channel (or to a neighboring identical part).

• A MOSFET that reads nearly 0Ω across the main path compared to others is a red flag.

3) Inspect the head cable path and connector condition

A surprising number of "031006 + fuse blown" cases trace back to:

• Ink contamination, moisture, or residue bridging pins

• Bent pins or damaged FFC/FPC traces

• A pinched or partially torn printhead cable

If there's contamination on the head connector, cleaning and correcting the underlying cause is critical-otherwise you may blow the replacement fuse again.

If the fuse replacement "works," is the problem solved?

If you replace F2 and the printer comes back without 031006, that's a good sign-but keep an eye out for:

• The error returning after a few prints

• Uneven nozzle groups missing (suggesting one channel is still weak)

• Heating/burning smell or unusual warmth near the MOSFET area

A fuse rarely blows "for no reason." If it blew due to a transient event you might get lucky, but if the root cause remains (head/cable short or marginal MOSFET), it can fail again.

If the new fuse blows immediately

If F2 blows right away, the most likely culprits are:

• Shorted MOSFET(s) in that head-drive channel

• Short in the printhead or head cable/connector

• Less commonly, a driver IC upstream commanding abnormal current, but that's usually secondary once MOSFETs/fuses are involved.

At that point, continuing to "try another fuse" is usually not productive until the short is found and corrected.

Addressing printer issues can be tricky because so much of it is hands-on and depends on measurements and inspection in real time. Because of that, we're not able to provide remote troubleshooting, step-by-step repair direction, or remote support for printer repairs. We do offer an in-person evaluation and repair service through our local diagnostic facility: printer repair service (https://bchtechnologies.com/printer-repair-service). Due to high demand, we run on a first-come, first-served basis, and it can take a few weeks before we can accept your printer for drop-off. Our services are set up to repair either an entire printer or specific parts, with clear instructions on how to proceed. We also want to be transparent that our rates aren't the cheapest option-so we strongly encourage self-help through online research. A great starting point is YouTube and our channel homepage: BCH Technologies on YouTube (https://youtube.com/@bchtechnologies). Use the search icon next to "About" on the right side of the menu bar to find videos by keyword. I receive dozens of messages daily asking whether I've made a video on a specific issue, and after nine years of uploading, it's hard to remember every single one-YouTube search is the fastest way to locate the most relevant content, and it may also suggest helpful videos from other creators.

Thank you again for your support and for choosing BCH Technologies-especially for following our motherboard removal guidance. I really appreciate you taking the time to test continuity and share the details (F1/B15 good, F2 open, and error 031006).