Troubleshooting Epson XP-15000 Error 031006 and Power Issues: A Detailed Repair Guide

Question:
I’ve been following your posts and am a customer of your store. I’m having trouble with my Epson XP-15000 printer. Initially, I encountered error 031006 and replaced the "K" fuse, which allowed the printer to restart. However, while moving the printhead, the printer started rebooting unexpectedly and clicking before shutting off permanently. Now it won't turn back on at all. I checked the CN01 power connector on the CG43STD (CF15 MAIN) motherboard and measured 10 ohms between pins 1 and 2, which seems abnormal. I also tested some nearby 3-pin components (which I assume are MOSFETs), and they didn’t appear shorted, though I didn’t desolder them. What component do you think I should replace to revive my printer?

Answer:

Understanding Error 031006 and What It Means

Error 031006 typically points to a power-related failure on the mainboard, usually caused by a short circuit. It's commendable that you identified and replaced the “K” fuse — this is often the first weak link to fail when a printhead shorts out a circuit. However, fuses usually blow to protect other components, so their failure is a symptom, not the root cause.

From your description, the problem may have spread beyond just the fuse.

Step-by-Step Analysis and Recommendations

1. Did the Printhead Cause the Initial Short?

One vital diagnostic step is determining whether you installed a new or used printhead before replacing the fuse. If the same (possibly damaged) printhead remained installed after the fuse blew, it might have caused recurrent shorts, damaging deeper layers of the motherboard circuitry.

When a printhead shorts the power circuit, it often affects fuses, voltage regulator ICs, MOSFETs, or even the microcontroller. If the new fuse blew again or the printer showed erratic rebooting behavior (as you described), a low-voltage power rail (e.g., converting 42V down to 3.3V or 5V) is likely damaged.

2. The Click and Permanent Power-Off

The “click” sound you heard could be from:

• A protection relay attempts to activate but then fails due to a low-voltage failure.

• A failed MOSFET is trying to switch under load but failing, tripping internal protection circuits.

• Or a buck converter chip experiencing catastrophic failure.

The fact that the printer now refuses to power up is a classic sign of damage to a critical power management IC (commonly known as a regulator chip or buck converter). These chips handle converting high-voltage input to the stable voltages used by the main logic board.

3. Power Connector Resistance Check

You mentioned a 10-ohm reading between pins 1 and 2 on the CN01 power connector. While some resistance is expected due to the presence of filtering capacitors and regulator coils, 10 ohms may indicate a partial short or failed component downstream from the connector.

4. MOSFET Testing Limitations

While it's a good idea to check the 3-pin components (likely MOSFETs or diodes), keep in mind that:

• Many issues won't show up in-circuit because surrounding components can “mask” a short.

• MOSFETs can fail partially, where they still show correct readings on a multimeter but no longer switch properly under load.

• Desoldering may be necessary for accurate testing, though it is admittedly difficult.

Suggested Repair Steps

1. Remove the printhead entirely before further testing. A damaged printhead will keep re-shortening any repairs you make.

2. Follow the power rail from the CN01 input. Use the 42V input and trace the path:

   • Look for a buck regulator chip (often labeled with part numbers like RT8205, RT8239, etc.).

   • Check for burned spots, slight bulges, or hot components.

3. If possible, use an oscilloscope or logic analyzer to verify that the low-voltage rails are active when you power on. No activity means your voltage conversion is not occurring — likely due to failed regulators or MOSFETs.

4. As a next step, if you’re comfortable with surface-mount rework, replace the regulator chip most directly connected to the power line showing abnormalities. This will usually be the first one downstream from the power input.

5. If the printer powers on but reboots intermittently, you may also have EEPROM or firmware corruption, though this is less likely than a hardware issue given your symptoms.

Please Note:
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.