Epson ET-2720 No Power After Paper Towel Was Left Under the Printhead: Mainboard, Fuse, and MOSFET Troubleshooting

Question

I watched your video about repairing an Epson ET-2720 printer with no power, including mainboard, formatter board, transistor, and MOSFET repair. I accidentally left a paper towel under the printhead, turned the printer on, and ran a head cleaning. The printer shut off by itself and has not powered on again. What could have caused this, and how can I fix it?

Answer

In your case, the printer does not appear to be showing a normal Epson error code because it is no longer powering on. When an Epson printer is completely dead, there may be no screen message, no blinking-light pattern, and no software error code available. That usually means the problem has moved from a mechanical or carriage issue into the power circuit, mainboard, or a safety-protection component.

Leaving a paper towel under the printhead can cause several problems. During a head cleaning cycle, the printhead and carriage may attempt to move while the paper towel is blocking the carriage path. At the same time, the pump system, cap station, and cleaning mechanism may be trying to pull ink through the nozzles. If the towel is jammed under the head, soaked with ink, or pushed into the capping station area, the printer can experience mechanical resistance, motor overload, or even an electrical short if liquid ink reaches the wrong area.

The most likely possibilities are:

1. The carriage or printhead was physically blocked.
   If the printhead could not move freely because the paper towel was under it, the carriage motor may have stalled. Normally, the printer should detect a carriage movement problem and stop with an error, but if the blockage caused enough stress or the circuit was already vulnerable, the mainboard may have been damaged.

2. Ink or moisture may have caused a short circuit.
   A paper towel under the printhead often becomes saturated with ink. If that wet towel touched the printhead contacts, carriage cable, sensor cable, or nearby electronics, it may have created a short. This is especially risky around the printhead FFC cables, carriage board, and mainboard connections.

3. A fuse on the mainboard may have blown.
   Many Epson boards use small surface-mount fuses to protect the circuit. If the printhead, carriage, or motor circuit shorted, one of these fuses may open. When that happens, the printer may appear completely dead or may power partially but fail to initialize. On some Epson models, these fuses are marked with labels such as F1, F2, or similar markings on the board, though the exact labeling depends on the board revision.

4. A MOSFET or transistor on the formatter/mainboard may have failed.
   Since your question is related to the "no power" repair video, this is another strong possibility. MOSFETs and transistors are used to control power delivery to different parts of the printer. If a short occurred during the head cleaning cycle, one of these components may have failed. A shorted MOSFET can sometimes prevent the printer from powering on at all.

5. The power supply could have gone into protection mode or failed.
   If the mainboard or load side developed a short, the power adapter or internal power supply may shut itself down for protection. In some cases, the power supply is still good, but it refuses to start because the printer board is shorted. In other cases, the power supply itself may be damaged.

The first thing I would do is unplug the printer completely and remove the paper towel. Then inspect the carriage path, printhead area, cap station, and inside the printer for loose pieces of towel, ink pooling, or anything stuck in the mechanism. Do not keep pressing the power button repeatedly, because if there is an electrical short, repeated power attempts can make the damage worse.

Next, inspect the printhead cable and carriage cable. If either cable has ink on the contacts, burn marks, corrosion, or bent pins, that can cause a no-power condition or damage the mainboard. Be very careful when removing or reinstalling FFC cables because one crooked cable can short multiple pins at once.

If you have a multimeter and are comfortable working with electronics, check the power supply output first. If the adapter or power supply is not producing the correct voltage, the printer will obviously not power on. If the power supply output is correct, then the problem is likely on the mainboard or a connected load, such as the printhead, carriage board, or motor circuit.

After that, the mainboard should be checked for blown fuses, shorted capacitors, damaged MOSFETs, or burned components. A blown fuse may show open continuity. A failed MOSFET may show a short between drain and source, depending on the circuit. However, replacing a blown fuse without finding the original short can cause the new fuse to blow again immediately. That is why it is important to check the printhead and cables before replacing parts on the board.

If the printer shut off exactly during the cleaning cycle, I would pay special attention to the printhead circuit and carriage assembly. A printhead short is one of the more common reasons Epson printers damage the mainboard. Sometimes the board can be repaired by replacing a fuse, transistor, or MOSFET. Other times, the printhead is also damaged, and installing a repaired board while the bad printhead is still connected can damage the board again.

In short, the issue is likely not the paper towel by itself, but what happened when the printer tried to run a cleaning cycle with the towel blocking or touching the printhead area. The most likely failure points are the mainboard fuse, MOSFET/transistor section, power supply, printhead cable, or printhead circuit. Since there is no displayed Epson error code, this should be treated as a no-power electrical diagnosis rather than a normal software-reset or waste-ink-counter issue.

Addressing printer problems can be complicated because many repairs require hands-on inspection. For that reason, we are not able to provide remote troubleshooting, step-by-step repair support, or guaranteed repair suggestions for individual printers. We do offer an in-person evaluation and repair service through our local diagnostic facility, BCH Technologies Printer Repair Service [https://bchtechnologies.com/printer-repair-service]. Because demand is high, repairs are handled on a first-come, first-served basis, and it may take a few weeks before we can schedule a printer drop-off. Our service can evaluate either the entire printer or specific parts, depending on the repair request, with instructions provided for how to proceed. However, we understand that our rates may not be the most economical option for every situation. For that reason, we highly recommend using self-help resources and online research whenever possible. You can start with YouTube or visit our YouTube homepage, BCH Technologies on YouTube [https://youtube.com/@bchtechnologies]. Use the search icon next to the "About" section on the right side of the menu bar to search for specific repair topics. I receive dozens of questions every day asking for videos on specific problems, and after making videos for the past nine years, it is difficult to remember every single one. YouTube's search function is usually the fastest way to find the most relevant video, and it may also recommend helpful videos from other channels.

Thank you again for watching our video and for reaching out. I hope this gives you a better idea of where the failure may be and what areas to inspect before deciding whether to repair the board, replace parts, or bring the printer in for diagnosis.