Troubleshooting a Blown Fuse and Solid Red Light on MZK L1800 (Epson 1390 Clone): Causes and Repair Options

Question:
I purchased an MZK L1800 printer from Amazon, but in the printer app, it shows up as an Epson 1390. It's less than three months old, and now it’s displaying a solid red light. I used a multimeter to test the fuse, which was initially good, but it blows as soon as I turn the printer on. Support via WhatsApp said both the motherboard and printhead are likely bad, though both should still be under warranty. They offered to send a new motherboard, but my business is suffering and I can't afford to wait a month. What exactly do I need to replace—just the motherboard and printhead, or should I include cables and fuses too?

Answer:
1. Printer Model Mismatch – Why the App Shows Epson 1390

This is a common occurrence with remanufactured or clone printers. The MZK L1800 model you bought is likely built on the Epson 1390 or 1400 platform, meaning it uses the same driver and board architecture. So, when it registers as an Epson 1390 on your system, that’s expected behavior—not a malfunction.

2. Blown Fuse at Startup – What's Going On

If your printer blows a fuse immediately upon powering on, despite the fuse testing good when the machine is off, that indicates a hard short circuit inside the printer. Possible culprits include:

• Shorted printhead: This is common and happens when internal circuitry in the head draws excess current.

• Fried MOSFET or voltage regulator on the motherboard: Power surges or heat damage can destroy these components, causing shorts.

• Damaged FFC (flat flexible) cable: Less frequently, the ribbon cable between the head and the board might have fine cracks or arcing.

The fact that your fuse pops every time you power on confirms this is not a random failure—the fuse is doing its job by preventing catastrophic damage due to an overload.

3. Support Diagnosis – Likely Fault in Main Components

Your support contact indicating the motherboard and printhead are both bad is unfortunately very likely true. Given that the printer is less than 90 days old, these parts should absolutely be covered, but we understand the urgency of not waiting weeks for replacements. So if you're planning to proceed with self-repair, here’s how to do it right.

4. What Needs Replacing – A Full Checklist

To safely bring your printer back online, we recommend replacing or inspecting the following components:

• ✅ Motherboard (Mainboard)
  This is your first target. If it’s shorted, it’s what’s blowing the fuse. Replace with a board specifically matching the MZK L1800 or a compatible Epson 1390/1400 clone with the same connector arrangement.

• ✅ Printhead
  These are fragile and often fail with little external sign. If it’s internally shorted, plugging it into a new board could immediately destroy that board. If support said it's shot, better to replace it than risk a repeat failure.

• ✅ Fuse
  Replace only with the same amperage (typically 1.25A or 2A; check the board markings). Do not use a higher-rated fuse.

• ✅ FFC Cables (Flat Ribbon Cables)
  If there’s visible damage (kinks, exposed metal, discoloration), replace them. Even if they look okay, replacing them is inexpensive insurance during a full repair.

5. Steps to Prevent Further Damage

Before applying power to your new components:

• Disconnect the printhead when testing your new motherboard for the first time. That way, if the head is still shorted, you won’t ruin the new board immediately.

• Use a current-limiting power supply or inline fuse holder, if available, during testing.

• Check for continuity across the FFC cables using your multimeter. Look for unwanted shorts between adjacent pins.

• Inspect your power adapter or power supply board—occasionally, damage originates from a faulty power source rather than internal components.

6. Getting Parts Without Delay

We carry compatible parts, including:

• MZK L1800 / 1390-compatible mainboards

• DX5-style printheads

• FFC cables and fuses

If you're located in the U.S., we typically ship within 2–3 business days. You can view our full selection and place orders through our printer repair service center [https://bchtechnologies.com/printer-repair-service].

If you’re unsure which parts you need, send us high-quality pictures of your motherboard and printhead area. We’ll help confirm compatibility before you order.

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 [https://bchtechnologies.com/printer-repair-service]. Given the high demand, we operate on a first-come, first-served basis. So, it might take a few weeks before we can get your printer to drop it 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 [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. Your trust in BCH Technologies means a great deal to us. We hope the guidance provided here helps you get your MZK L1800 back into action swiftly and reliably. Don’t hesitate to follow up if you need further assistance.