Epson 1390 Prints but No Ink Comes Out After Printhead Cleaning: Why the Fuse Blows and What to Test Next

Question: I have an Epson 1390. After my husband took apart the printhead to unclog white ink and put it back together, the printer acts like it wants to print but no ink comes out. Tech support had us check the fuse in the back-it was blown. We replaced it and it blew immediately. They say it's the motherboard. What do you think?

Answer:

Based on your description, the most important detail is this:

• The printer still goes through the motions like it's printing (paper feeds, carriage moves), but no ink comes out.

• The fuse was blown, and when you replaced it, it blew immediately.

That pattern strongly points to the nozzle firing power circuit-not an ink supply problem. In other words, the printer is "printing mechanically," but the printhead is not being electrically driven to fire ink. On the Epson 1390 / 1400 / 1430 / L1800 family, this usually traces back to a blown head-firing fuse and the reason it blew.

1) Why the printer can still "print" even when no ink comes out

Epson printers can move the carriage and feed paper even when the head cannot fire. Those motions are controlled by motors, sensors, and logic signals. But ink actually coming out requires the printhead to receive high-frequency firing pulses and the correct drive voltage.

If the fuse that supplies the printhead firing circuit is open (blown), the printer can look normal while producing blank pages-because the head simply cannot fire.

2) If the new fuse blows immediately, something is shorted (and that "something" matters)

A fuse doesn't blow for no reason. If it blows right away, the printer is likely experiencing a short circuit on the head firing line. The two most common causes after a head has been taken apart or reinstalled are:

A) A shorted or damaged printhead (most common trigger)

Disassembling a printhead (especially with white ink clogs) can easily lead to internal damage, fluid intrusion, or electrical shorting. White ink is also heavier and can create more clog pressure and handling stress.

If the printhead has an internal short, it will repeatedly blow the fuse because the head is effectively "pulling too much current" the moment power is applied to the firing circuit.

B) A short or blown driver IC on the mainboard (also common)

Even if the printhead caused the first fuse blow, the driver components on the mainboard can also fail. On these Epson models, the mainboard contains driver circuitry (often MOSFET/driver IC stages) that sends the firing pulses to the head. If a driver IC is shorted, you'll see the same behavior: fuse blows immediately.

So when tech support says "motherboard," they might not be entirely wrong-but it's usually not a guess you make first. You determine whether the board is bad, the head is bad, or both-because a bad head can also take out a good board.

3) What to test first: printhead with a multimeter (before replacing more fuses)

Because the fuse is blowing instantly, you want to identify whether the printhead is shorted. A multimeter test can often confirm this quickly.

You referenced the correct tool for this process here:

• Printhead multimeter test sheet for Epson L1800/1390 (https://bchtechnologies.com/products/test-sheet-for-l1800-1390-printhead-testing-with-multimeter-digital-download-instant-download-delivered-to-your-email?_pos=1&_sid=e6eb61c9a&_ss=r)

High-level testing logic (without getting overly technical):

• If the printhead shows abnormal readings (near-short or clearly outside expected ranges), the head is likely the reason the fuse blows.

• If the printhead tests fine, then the board is more likely shorted (driver IC, power rail, or another component).

Important: If you keep replacing fuses without testing, the fuse is just doing its job-protecting the board from damage. Replacing it repeatedly can lead to bigger failures if the underlying short remains.

4) Also check the mainboard driver IC and look for other shorts

You also mentioned checking whether the driver chip IC is blown on the mainboard, and that's a critical step. If a driver IC is shorted, it can blow the fuse even with a good printhead.

In addition to the IC, other things that can trigger immediate fuse failure include:

• A pinched/damaged printhead ribbon cable (shorting conductors)

• Incorrectly seated ribbon cables (misalignment can short adjacent pins)

• Ink or cleaner fluid contamination on contacts (conductive residue can create shorts)

• Burnt traces or components on the board (sometimes visible as a dark spot or smell)

A very common scenario is:

1. Printhead was disturbed or opened to address white ink clogging

2. Something shorted during reassembly (head internal, ribbon, or contact contamination)

3. Fuse blew (protective event)

4. Replacing the fuse without correcting the short makes it blow again immediately

5) Is it "the fuse" or "the motherboard"?

From your symptom pattern, the fuse is definitely involved, because it's blowing and it directly relates to the head firing circuit. But the bigger question is why it's blowing.

A good way to frame it:

• The fuse is the failed part you can see.

• The printhead or the mainboard is usually the reason it failed.

So tech support saying "motherboard" may be correct in some cases, but the most reliable approach is:

1. Test the printhead (because a bad head can instantly blow the fuse and can also damage the board)

2. Inspect/test the mainboard driver circuitry (because a blown driver IC can also blow fuses repeatedly)

3. Inspect the ribbon cables and connectors (because reassembly issues are extremely common after head work)

If the printhead is shorted, replacing the mainboard alone won't fix it-it may just damage the new board. Likewise, if the board driver IC is shorted, replacing the head alone won't fix it.

Addressing printer issues can be a complicated affair due to the hands-on nature of the problems. So, we're not able to provide remote troubleshooting, suggestions, or support for printer repairs. We offer an in-person evaluation and repair service via our local diagnostic facility: BCH Technologies printer repair service (https://bchtechnologies.com/printer-repair-service). Given the high demand, we operate on a first-come, first-served basis, so it may take a few weeks before we can get your printer scheduled for drop-off. Our services are structured to repair either a whole printer or specific parts, with clear instructions on how to proceed. However, we acknowledge that our rates aren't the most economical. Thus, we highly recommend that you resort to self-help via online research. You can start by checking out YouTube or visiting our YouTube channel's homepage: BCH Technologies YouTube channel (https://youtube.com/@bchtechnologies). Look for specific videos using the search icon next to "About" on the right-hand side of the menu bar. I receive dozens of queries every day asking about videos for specific topics. Having created videos over the past nine years, it's challenging to remember every single one. Therefore, using YouTube's search function would be most efficient. Plus, YouTube might suggest relevant videos from other channels that could assist you.

Thank you again for reaching out. I truly appreciate the details you shared-especially the "fuse blew immediately" part-which is a strong diagnostic clue. I hope the multimeter test helps you determine whether the printhead is the trigger, whether the driver IC on the board is damaged, or whether both need attention.