Comprehensive Guide to Troubleshooting Epson Stylus Photo 1390 DTF Printer Mainboard Issues: A Q&A Breakdown

Question:

Hey thanks for helping me out with my previous problem. My printer is an Epson Stylus Photo 1390 DTF. Action I have taken: Changed the main board, changed ink line and printhead cables (secondhand but visually fine), new printhead but still nothing on my encoder sensor. The printer powers on, WIMS works, the fans work and you can see the feed the film back-and-forward working. I have tested with Fuse2, its works but i cant find the Fuse1. What will you do next? Also would like to attempt repair on the board I pulled out if only to learn more. On top of which, the replacement mainboard I was sent seems to be dead in the water. I'm feeling quite defeated. However, it is very helpful. Thank you!

Answer:

Thank you for your outreach. We greatly appreciate our engaged supporters. We at BCH Technologies sincerely appreciate your feedback, especially regarding engaging with our YouTube channel [https://youtube.com/@bchtechnologies]. Your input makes our technical content and expertise possible. Next, we will go through the problems you are facing with your Epson Stylus Photo 1390 DTF Band, which has fallen off the printer, and possible solutions.

Diagnosing the Issue:

Since your printer is powering up in some manner with components like WIMS and fans and film feed buttons working, that means the power delivery system is at least partially working. The main switch in the back powers the WIMS, which is the breakout board for paper feed/reverse. However, it sounds like the printer's mainboard is not powered up. If the red light of your sensor encoder still keeps off, then we would like to tell you that there might be a problem with the mainboard. Below are a few steps that you can try to troubleshoot this problem.

1. Power Cycle the Printer

While this may seem simple, doing a power cycle [3] of your encoder sensor can reset some internal pathways and fix the small bugs preventing specific parts from working. To do this:

Disconnect your printer from the power for a few minutes.

Wait for a while, reconnect the power, and try turning on the printer.

This process will reset the printer's internal setup, eliminating any temporary conflicts that might have triggered a conflict and preventing your printer from working.

2. Loose or Broken Connections

Because some pieces are firing and others are not, it's necessary to check over all the internal connections closely:

Could you open the printer and check for any loose connection between the mainboard and some parts like the printhead or encoder sensor power source, etc? Some printers doesn't use Epson's OEM power supply, rather, they use a generic power supply with a buck converter. Sometimes, they need to follow protocols and connect them loosely and thus may fall off during printing.

Could you make sure all cables are firmly attached and there's no fraying in the wiring?

A loose connection, for instance, can easily keep the encoder sensor from getting the juice it needs. Worse, damaged cables can create spotty symptoms that are not readily visible.

3. Examine the Fuses

The part about successfully testing the fuse is great — that's a critical piece. There is only one fuse on the mainboard, so you've tested it. Here’s what you can do:

If Fuse1 is blown, its replacement should solve the problem. Remember that fuses don't burn out for no reason, so you have to check for other shorted parts around the area that might be pulling too much current.

4. Inspect the Mainboard visually

At other times, the problem can be diagnosed with a careful visual inspection of the mainboard. Here’s what to look for:

Burnt spots or burnt out: Charring on components is a tell-tale sign of a part failing from too much heat or a power surge.

Swollen or leaking capacitors can prevent power from being evenly distributed to some components, such as the encoder sensor.

Broken or cracked connectors: Inspect all solder points; a crack in any one will prevent the proper flow of electricity.

Often, small and inexpensive elements (capacitors, connectors) cause the problem, and replacing them can give your printer another life.

5. Use a Multimeter to Check the Resistance of the Power Components

You can test the mainboard components with a multimeter to determine the cause. Here’s how:

Test continuity on the most critical parts of the board (main power line and connectors for encoder sensors).

Check all different voltage points in the board and verify that the proper voltage supplies every component. The encoder sensor needs voltage to work, so checking this can help us narrow down the issue.

6. Testing the Encoder Sensor

Encoder Sensor Problem: The sensor fails, or it does not get power from the mainboard. If every other part seems good, consider replacing the encoder sensor if you notice this issue.

7. Find the Mainboard

So the new mainboard you got isn´t working suitably. You could imply that the other part is defective. There is a slightly higher probability that replacement parts won't be broken, but it can still happen due to reasons involving shipping or manufacturing. Wow — if the part is under warranty, it is all worth communicating with a supplier for return or exchange.

8. They are trying to fix the old Mainboard

The above actions can help if you want to fix your initial mainboard. Focus on:

Checking fuses and replacements if needed. Checking for Damaged Capacitors and MOSFETs

Inspecting voltage regulators to confirm they stepped down the mains' voltages at proper levels for components.

If you know how to solder, you can replace these parts yourself, but be sure because an incorrect repair may cause even more problems.

You can also send the mainboard to us for repair (https://bchtechnologies.com/collections/printer-repair-service/products/fast-track-mainboard-repair-l1800-xp-15000-et-15000-wf-7610-7620-wf-7110-wf-7710-7720-et-8550-et-2720-et-2750printer-mainboard-formatter-board-motherboard-troubleshooting-and-repair) We will test and fix it, then put it on our DTF production machine and make sure everything checks out and the mainboard is of production quality. This differs from getting a replacement mainboard from the internet, in which the mainboard might be harvested from a non-working machine and never tested on an actual DTF printer.

Advice and BCH Technologies Services

Fix That Printer: Background Printing a printer can be extremely complicated and requires a skilled hand. We are glad to introduce our suggestions, but BCH Technologies is not responsible for conducting telephonic troubleshooting or other such device-specific responses.

However, we provide a drop-off service to our local diagnostic facility so we can inspect and repair it on-site (Learn more about our printer repair services here: [https://bchtechnologies.com/printer-repair-service]). Because of the high demand for this service, we take them in order, so it may be a few weeks before we can diagnose your printer. We will provide detailed shipping instructions for you to mail the printer or local drop-off.

We offer services like complete printer repair and common parts like the mainboard. Although our rates are not necessarily the most cost-effective, we recommend self-troubleshooting first. We also provide additional support materials in our extensive guides and videos on our [YouTube channel. ](https://youtube.com/@bchtechnologies) You can search for your problem to find solutions there or even from other creators.

Again, thank you for reading. We hope this post has resolved your issue with the printer. Should you have any other questions or need help with a repair, you can contact me here.