Why an Epson WF-3620 Prints Internal Reports but Jams When Printing from a Computer or Phone

Question

I watched your video about stopping paper jams, and it was the best and most detailed explanation I could find. However, my Epson WF-3620 still has a strange problem. The printer can print its own internal reports and test pages without any trouble. But when I print from a computer or phone, the paper feeds in normally, then stops abruptly just below the printhead and gives a paper jam message. Why would the printer be able to print its own pages but jam only when printing my documents? Could this be some kind of obsolescence counter?

Answer

In your case, the fact that the Epson WF-3620 can print internal reports and test pages but fails when printing from a computer or phone is a very important clue. This usually means the printer's basic paper feed system is not completely dead. The pickup roller, separation pad, paper tray path, and basic paper movement are working well enough for the printer to complete its own built-in print jobs.

However, printing an internal report is not the same as printing a document sent from a computer or mobile device. When the printer prints its own internal report, it already knows what kind of page it is going to print. It usually assumes a standard paper source and a standard paper size, such as Letter or A4. It does not need to interpret as much outside print data, and it may not need to perform the same level of paper-size verification that it does during a normal print job from Windows, macOS, iOS, Android, or a network print command.

When you send a job from a computer or phone, the printer has to compare several things: the paper size selected in the driver, the paper size set on the printer, the paper source selected, the paper type, margins, orientation, and the physical paper movement detected inside the machine. If the printer expects one paper size but detects something different, or if one of the sensors fails to confirm the paper's position at the expected time, the firmware may stop the job and report a paper jam even though the paper is not truly crumpled or stuck.

For the Epson WF-3620, this kind of symptom can point to a malfunctioning page width sensor or the PIS sensor. The page width sensor helps the printer determine whether the paper width and position match what the printer expects. If that sensor is dirty, blocked, weak, misaligned, or failing electronically, the printer may feed the paper correctly at first but stop once the paper reaches the area below the printhead. That is often the point where the printer wants confirmation that the paper is in the correct position and size before continuing.

The PIS sensor can also be involved. Depending on the model and the printer's internal design, this sensor helps the printer confirm paper position or movement through the print path. If the PIS sensor does not detect the paper correctly, the printer may think the paper has stopped, skewed, arrived too late, arrived too early, or does not match the requested print condition. The result can be a false paper jam message.

This explains why the printer may print its own reports but fail on outside print jobs. The internal report does not challenge the printer in the same way. It may use a default page size and a predictable routine. A print job from a computer or phone forces the printer to check the page size, paper source, and job settings more carefully. That extra verification is where the error may be happening.

I would first check the simple causes before assuming the printer has reached an "obsolescence counter." Epson printers do have maintenance counters and waste ink pad counters, but those usually produce specific service messages, not a paper jam that occurs only when printing from external devices. A waste ink counter or service-life counter would normally block printing more broadly, including internal functions, or show a message related to service being required. Since your printer can still print internal pages, this looks more like a sensing, paper-size, or communication mismatch issue than a planned obsolescence counter.

Here are the areas I would check:

First, confirm that the paper size selected on the printer matches the paper size selected in the computer or phone. For example, if the printer is set to A4 but the computer is sending Letter, or vice versa, the printer may feed the paper and then stop when the detected position does not match the job. Also check whether the job is being sent to Tray 1, rear feed, or another paper source that does not match the loaded paper.

Second, check the print driver settings. On a PC, open the printer preferences and make sure the paper size, paper type, orientation, and source are correct. Try printing a very simple one-page document using plain paper, standard quality, and the correct paper size. Avoid borderless printing, envelopes, labels, thick paper, or custom sizes during testing.

Third, try printing from a different program. For example, print from Notepad or a basic PDF viewer rather than a browser or photo app. Some applications send custom paper sizes or scaling instructions, and that can confuse a printer that already has a weak sensor.

Fourth, inspect the paper path carefully. Even if internal reports print correctly, a small scrap of paper, dust, dried ink mist, or a loose piece of debris near the sensor area can cause intermittent detection problems. Use a flashlight and look around the area where the paper stops, especially below the printhead path and around the paper exit and registration area. Do not force the carriage or sensor flags.

Fifth, check for any small plastic sensor flags that may be stuck, broken, or not springing back correctly. Many Epson paper jam errors are caused by a sensor flag that does not move freely. The printer may feed the page, but if the sensor flag does not trigger at the correct time, the printer assumes a jam.

Sixth, clean the accessible sensor areas gently. If you can identify the page width sensor or related optical sensor area, use gentle air and a lint-free swab where appropriate. Do not flood the printer with liquid. Inkjet printers often collect paper dust and ink mist inside the paper path, and optical sensors can become unreliable when dirty.

Seventh, reset the paper settings on the printer and reinstall or update the printer driver. If the printer's internal paper settings and the computer's driver settings are not communicating correctly, reinstalling the driver or removing and re-adding the printer may help. Also try USB printing if you normally print over Wi-Fi, or try Wi-Fi if you normally print through USB, just to separate a driver or communication issue from a mechanical one.

If the paper always stops in the same place, just below the printhead, that strongly suggests the printer is feeding paper successfully but failing at the confirmation stage. In that case, I would focus less on the pickup roller and more on the page width sensor, PIS sensor, paper-size detection, paper-position detection, and driver paper-size settings.

Addressing printer issues can be a complicated affair because many of these problems require hands-on inspection. For that reason, we are not able to provide remote troubleshooting, personalized repair guidance, or direct support for individual 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, repairs are handled on a first-come, first-served basis, so it may take a few weeks before we can accept your printer for drop-off. Our service can be structured around repairing the whole printer or specific parts, with instructions provided for how to proceed. However, we also understand that our repair rates may not be the most economical option for everyone. For that reason, we highly recommend self-help through online research. A good place to start is YouTube, including our channel homepage, BCH Technologies on YouTube [https://youtube.com/@bchtechnologies]. Once there, use the search icon next to "About" on the right-hand side of the menu bar to search for specific topics. I receive dozens of questions every day asking which video covers a certain issue, and after creating videos for more than nine years, it is difficult to remember every single one. Using YouTube's search function is usually the fastest approach, and YouTube may also suggest helpful videos from other repair channels.

Thank you again for watching the video and for sharing such a clear description of the problem. Since your WF-3620 can still print internal pages, I would not assume the printer is finished yet. I would first investigate the page width sensor, PIS sensor, paper-size settings, and driver settings before replacing major parts or giving up on the printer.