Epson ET-8550 Paper Output Tray Not Opening After Improper Shutdown: Do You Need a Power Supply, Mainboard, or Another Part?

Question

I have an Epson EcoTank ET-8550 and need help finding the correct part for a problem. The printer was not turned off properly and was unplugged while still powered on. After that, I started getting a message saying the printer could not perform a printhead nozzle check. Power cleaning still works, but the paper output tray does not open and the printer will not print. I watched a few videos online and was told by a technician that both the power supply and motherboard may need to be replaced. Can you help me identify what may be wrong and what part I may need?

Answer

From your description, there are likely two separate things happening: the improper power-off warning and the mechanical/electronic issue with the paper output tray.

The message about the printer not being turned off correctly is usually a warning caused by the printer losing power before it completed its normal shutdown sequence. On many Epson EcoTank models, including printers like the ET-8550, the printer expects the power button to be used so it can park the printhead, cap the printhead properly, and shut down the internal electronics in the correct order. If the printer is unplugged while still powered on, it may display a warning when restarted.

That warning by itself does not automatically mean the power supply or mainboard is bad. In many cases, you can simply dismiss the warning and continue troubleshooting the actual problem. The warning is the printer telling you that the previous shutdown was abnormal, not necessarily giving you a specific failed-part diagnosis.

The more important symptom is that the paper output stacker tray does not extend when commanded from the touchscreen. On the Epson ET-8550, the output tray is motorized. When you print, the printer normally extends the tray automatically. If that tray does not open, the printer may stop the print job because it thinks the paper path or output area is not ready.

The first thing I would check is whether the tray is mechanically stuck or whether the printer is failing to drive the tray motor. Sometimes the tray can bind from being pushed in, obstructed, misaligned, or partially jammed. If the touchscreen command does not open the tray, you can carefully grab the output tray and gently force it outward by hand. Do not yank it aggressively, but try to pull it out evenly and see whether it is simply stuck. After the tray is extended, try printing again.

If the printer prints after you manually pull out the tray, then the printhead, power supply, and mainboard may not be the main problem. In that case, the issue may be related to the tray mechanism, tray motor, sensor, or a mechanical obstruction in the output tray assembly.

If the tray still will not work even after being manually extended, or if the printer still refuses to print, then the problem may be more electronic. The mainboard is one possible suspect because the mainboard controls many of the printer's motor functions, sensors, and communication between the touchscreen and the printer's internal mechanisms. If the printer accepts touchscreen commands but does not activate the tray motor, the signal may not be reaching the motor, the motor may have failed, or the mainboard may not be sending the correct command.

However, I would be cautious about replacing both the power supply and the motherboard right away unless there is stronger evidence. A failed power supply usually causes broader power-related symptoms, such as the printer not powering on, shutting off randomly, clicking, showing no display, or failing to initialize properly. Since you mentioned that power cleaning still works, that suggests the printer is powering up and at least some major functions are operating. That does not completely rule out a power supply issue, but it makes the power supply less likely than a tray mechanism, tray motor, sensor, cable, or mainboard-related issue.

The "couldn't perform printhead nozzle" message may also be connected to the tray problem rather than a printhead problem. A nozzle check requires the printer to feed paper and prepare the output path. If the printer cannot open the output tray or thinks the tray is not in the correct position, it may block the nozzle check because the printer cannot safely complete the print operation. Since you said power cleaning works, the printhead maintenance system is at least partially functional. Power cleaning does not require the printer to output a printed page, but a nozzle check does.

Here is the order I would approach the troubleshooting:

First, dismiss the improper shutdown warning if the printer allows it. That message is usually not the main repair issue.

Second, manually extend the output stacker tray and see whether the printer will print or perform a nozzle check. If it prints with the tray manually extended, the issue is likely related to the motorized tray operation rather than the printhead or power supply.

Third, inspect the tray for anything blocking movement. Look for paper scraps, broken plastic, misalignment, foreign objects, or signs that the tray was pushed in at an angle.

Fourth, listen closely when commanding the tray to open from the touchscreen. If you hear a motor trying to run but the tray does not move, that points more toward a mechanical jam, stripped gear, or damaged tray mechanism. If you hear nothing at all, that may point toward the tray motor, motor cable, sensor, or mainboard.

Fifth, check whether the printer shows any specific Epson error code. You did not mention a numbered code such as 000031, 000033, 031006, 100016, or a scanner/printer error code. If the printer displays an actual code, that code would be very important because Epson error codes can narrow the problem to a specific system, such as the paper feed, carriage movement, scanner, mainboard, or other mechanism. Without a specific code, the symptom points mainly to the output tray system and possibly the mainboard.

If a technician already diagnosed the mainboard and power supply, I would ask what tests led them to that conclusion. For example, did they test voltage output from the power supply? Did they verify that the tray motor is receiving voltage? Did they inspect or test the tray motor cable? Did they confirm the tray mechanism is not jammed? If those tests were not done, replacing both the power supply and mainboard may be an expensive guess.

Based on the symptoms you described, I would not start by assuming both the power supply and motherboard must be replaced. I would first test whether the printer can print with the output tray manually pulled out. If it can, then the most likely problem is somewhere in the output tray mechanism, tray motor, tray sensor, or the control signal going to that assembly. If it still cannot print and the printer gives additional errors, then the mainboard becomes a stronger possibility.

Addressing printer issues can be a complicated affair because many of these problems require hands-on inspection and testing. For that reason, we are not able to provide remote troubleshooting, repair suggestions, or direct repair support for printer repairs. 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, we operate on a first-come, first-served basis, so it may take a few weeks before we can accept your printer for drop-off. Our services are structured to repair either the whole printer or specific parts, and we provide clear instructions on how to proceed. However, we understand that our rates are not the most economical option. For that reason, we strongly recommend self-help through online research whenever possible. A good place to start is YouTube, including our channel homepage at BCH Technologies on YouTube [https://youtube.com/@bchtechnologies]. Once you are on the channel page, use the search icon next to the "About" tab on the right-hand side of the menu bar to look for videos related to your exact issue. I receive dozens of questions every day asking for videos on specific topics, and after making videos for more than nine years, it is difficult to remember every individual video. Using YouTube's search function is usually the fastest way to find the most relevant content, and YouTube may also recommend helpful videos from other channels.

Thank you again for reaching out and for supporting BCH Technologies. I hope this gives you a better starting point before purchasing expensive parts like a power supply or mainboard. In this case, I would begin with the output tray test first, then move toward electronic diagnosis only if the printer still refuses to print after the tray is manually extended.