Understanding Error Code 0x42 on Procolored L1800 After Printhead Cleaning

Question:

Following your video on the Procolored L1800 printer, I cleaned and flushed the printhead. After putting everything back in, I powered it up, but I saw two blinking lights in the center of the left panel.

I plugged in my WIC diagnostic software and got ERROR 0x42 for all 6 ink channels, which means a bad printhead, bad printhead PCB, or bad cable. I had also read on a T-shirt printer forum that reseating the ribbon cable into the printhead solved a similar problem for someone else, but even after reseating my ribbon cables, the error persists.

The printer is well maintained and cleaned every day. Everything has been replaced -- motherboard, capping Station, and the printhead is only six months old. I took it out as ink buildup seemed to start screwing up my prints. Could this flushing have harmed the printhead? For that alone, I don't think I should replace the ribbon cable, printhead, or dismantle the printer? Any advice would be greatly appreciated.

Answer:

Understanding Error Code 0x42

The autodetect on the X-Hot during flush has failed, leading to error code 0x42 (Printhead has failed). In brief, this indicates that the head thermistor registered an abnormal temperature. At startup, the printer runs a voltage test on the printhead to measure the thermistor's conductivity.

• Error 0x40: No disconnection in the printhead (thermistor conductivity does not change).
• Error Code 0x41: Low temperature (thermistor change detected - but too low).
• Error code 0x42: Erroneous temperature (short inside the printhead).

0x42 error is an indication of an internal short in the printhead. We can burn the F1 fuse on the mainboard to continue using the printer in this state, and it is worse damaged.

Possible Causes and Solutions

FFC cable incorrectly inserted

• Reensure the FFC (flat flexible cable) is seated properly in both the mainboard and printhead. A loose or misaligned cable can trigger errors.

Mainboard Issue

• If the printhead is new and the FFC cables are secured firmly, the mainboard could be defective. Test with another mainboard if possible to eliminate this option.

Printhead – Faulty (Most Likely Cause)

• The 0x42 error is most commonly caused by an internal short in the printhead itself. This can happen due to:
• Residual moisture inside the printhead after flushing.
• Overheating during cleaning.
• Printhead electrical failure—inside the printhead.

Possible Recovery Option

Bizarrely, some users have been successful after turning the printer off and letting it sit overnight, finding the printhead working again the next day. This indicates that locked-in moisture could cause temporary shorts that clear as the ink dries.

Recommended Next Steps

• If that doesn't work after holding up overnight, it's probably time for the print head replacement.
• If you are replacing the printhead, use a compatible and genuine printhead for your model.
• If the mainboard is also believed to be affected, test another board in the printer before replacing more parts.

Printer problems are one of the most complex problems to fix, mainly because they are physical. We cannot, however, offer remote troubleshooting, support, or printer repair advice. However, we do provide an in-house mechanical evaluation and a possible repair at our in-house diagnostic facility (https://bchtechnologies.com/printer-repair-service). Please note that due to our customer demand, all assessment and repairs are first come, first served, and as such, could result in a wait time of a few weeks. You will learn about complete printer repairs, specific parts needing service or replacement, and steps to resolve the issue.

Having said that, we realize this isn't the cheapest repair option for our customers. When possible, please make use of self-help options, including online resources. For this our very first one tour channel can make for you is search a solution on YOUTUBE (https://youtube.com) for our channel home page (https://youtube.com/@bchtechnologies). Low-key, no small talk, use the search icon next to “About” in the menu bar to find what you care about. Note that we have made a ton of videos over the years, so the most efficient means of searching is by topic. Finally, YouTube might recommend other creators' relevant content to help you troubleshoot.

Thank you so much for writing to us! We appreciate your support and look forward to assisting you with all your printing needs.