Troubleshooting Epson Printer Power-Off Issue: Fixing Transistor Shorts on Main Board
- By Kevin Day
- On Dec 02, 2024
- Comment 0
Question:
I’m troubleshooting an Epson printer that consistently powers off during the initialization process. I have a background in electronics and have taken the following steps to diagnose the issue:
I’ve replaced the main board (purchased from China), the printhead, the CSIC board, and the FFC cable. Additionally, I’ve checked the resistance on the ASF motor, pump motor, and CR motor, and they all test fine. The 2-amp fuse on the power supply remains intact. Despite all efforts, the issue persists. What could be causing this?
Based on your description, the issue may be related to the flat flexible cable (FFC) connected to the printhead or the printhead itself. Here’s why and how to address the problem:
For those looking to tackle repairs independently, we encourage exploring our YouTube channel [https://youtube.com/@bchtechnologies]. You’ll find hundreds of tutorials, and the search feature can help you locate videos tailored to your issue.
Thank you for your detailed question and for choosing BCH Technologies. We hope this helps you fix the problem and restore your printer to working condition.
I’m troubleshooting an Epson printer that consistently powers off during the initialization process. I have a background in electronics and have taken the following steps to diagnose the issue:
- Upon power-on, the CR motor moves the carriage to the home position, then to the far right, and back home.
- The low-ink LED turns on, and I press the ink button. The carriage cycles through ink positions to detect cartridges needing replacement.
- Once all six cartridges are installed, the low ink indicator turns off, and the pump activates to prime the head, and the ink drains (visible in a clear waste line).
- Finally, the carriage moves to the right, and this is when the printer powers off.
I’ve replaced the main board (purchased from China), the printhead, the CSIC board, and the FFC cable. Additionally, I’ve checked the resistance on the ASF motor, pump motor, and CR motor, and they all test fine. The 2-amp fuse on the power supply remains intact. Despite all efforts, the issue persists. What could be causing this?
Answer
Thank you so much for contacting us for help with this issue. I'm sorry for not addressing your question sooner. Printer problems like this are always time-sensitive, and I appreciate your detailed explanation. At BCH Technologies, we’re grateful for your engagement and support, including your interactions on our YouTube channel [https://youtube.com/@bchtechnologies]. Your feedback is invaluable in helping us expand our knowledge and refine our solutions.Based on your description, the issue may be related to the flat flexible cable (FFC) connected to the printhead or the printhead itself. Here’s why and how to address the problem:
Analyzing the Issue
-
FFC Cable to the Printhead:
The smaller power cable running to the printhead might have an internal short. A damaged cable could cause intermittent power surges, which would lead to the repeated failure of the Q10 and Q11 transistors on the main board.
- How to Check: Inspect the FFC cable for visible wear, creases, or burns. Use a multimeter to test for continuity and ensure no short circuits are present. If any faults are found, replace the cable with a high-quality replacement.
-
Printhead Issues:
Even new or replacement printheads can have defects, mainly if sourced from unverified suppliers. A faulty printhead may draw excessive current during the priming sequence, triggering the main board to shut down.
- How to Test: Swap the current printhead with a verified working printhead, ideally from a trusted source.
-
Other Components:
Although you’ve replaced several parts, issues with the new formatter board or CSIC board cannot be ruled out, especially if they were purchased from unreliable suppliers. Defective replacement components often cause symptoms that mimic the original problem.
Recommended Steps
- Replace the FFC Cable: Replace the FFC cable on the printhead with a verified new cable. This is often the most common culprit in similar cases.
- Verify Printhead Functionality: Ensure the printhead is compatible and sourced from a trusted supplier. Test with a working printhead from another printer to confirm the issue is not related to the printhead.
- Inspect the Formatter Board: If the problem persists, consider sourcing a main board from a reliable distributor to rule out manufacturing defects.
Final Thoughts
Due to the complexity of the hardware, addressing printer issues like these often requires in-person diagnostics. While we cannot provide remote troubleshooting or repairs, we offer in-person evaluation and repair services through our local diagnostic facility [https://bchtechnologies.com/printer-repair-service]. Services cover complete printer repairs or specific part replacements on a first-come, first-served basis.For those looking to tackle repairs independently, we encourage exploring our YouTube channel [https://youtube.com/@bchtechnologies]. You’ll find hundreds of tutorials, and the search feature can help you locate videos tailored to your issue.
Thank you for your detailed question and for choosing BCH Technologies. We hope this helps you fix the problem and restore your printer to working condition.