Why is my Epson printer's power button working, but other buttons and LCD screen are not responding? Troubleshooting Tips

Customer Inquiry
As for now, I am facing an issue with my Epson printer. The power button is terrific; I can turn on the printer from it, and it illuminates as well, but all other keys are not working, and the LCD screen is not responding. Is the power button a separate flex cable from the rest of the control? Fortunately, everything else works with the printer, so what should be wrong? Thanks for your time.
 
Answer:
Thanks for your follow-up, and I apologize for not getting back to you sooner. I know how annoying these issues can be, and I appreciate your patience. At BCH Technologies, we can never thank you enough for your engagement and support regarding our YouTube channel (https://youtube.com/@bchtechnologies). Thanks for being a part of our community. Your feedback is essential to our improvement and growth in technical expertise.
 
Does the Power Button Use a Different Flex Cable?
Yes, indeed, in many printers—including the Epson series—the power button usually employs a separate circuit or flex cable from the rest of the control panel, which contains the other buttons and the LCD screen. The connection for the power button is normally a clearer and more straightforward path to the mainboard, which allows the mainboard to toggle just the printer's power functions.
 
The LCD screen and other buttons are typically controlled through a more sophisticated control panel system based on a standard flex cable (or shared data lines) for power and data communication to the mainboard. Since the power buttons are working but the other controls are not, this can indicate that there is a flex cable issue or any part of a control panel.
 
Why Other Buttons and LCD Screens Could be Malfunctioning
There are a few possible explanations for the problem you described, where the other buttons and LCD screen are not responding, but the power button works just fine:

1. Flex Cable Misalignment/Damage: Possibly the most common issue, this could be a result of a misaligned or damaged flex cable. One possibility is that the flex cable connecting the LCD and button panel is not seated correctly, or a pin is bent, interrupting the connection. With everything reassembled, it can be mangled just enough such that anything but the power button doesn't work and prevents anything from working.
2. Character Faulty LCD Driver Circuit: The circuit that powers and communicates with the LCD and buttons could be damaged. This would account for the other controls being non-responsive but would make the power button functional. The LCD driver circuit is usually a module separate from the printer's mainboard but is critical to the control panel operation.
3. Powers Up to Power Distribution: The power button has its own power line, but due to an issue like one of the flex cable power lines or a blown fuse, the rest of the control panel is not receiving enough power. If the control panel power distribution is interrupted, the LCD and other buttons will not function.
4. Control Panel Hardware Failure: The LCD screen and buttons are integrated into a typical control panel assembly. If any internal hardware in the panel is damaged or creates a fault through testing—and that could be anything from the screen to a button to the circuits underneath—it might cause the whole assembly to cease to function except for the power button. In this case, you might want to look at the control panel more closely for any signs of internal damage.

 
What to Do Next
So here are a few steps you can follow to help diagnose and possibly resolve the problem:

• Check that all flex cable connections are firmly seated. Unplug and then plug back in the flex cables associated with the control panel and the mainboard. Check for bent or damaged pins, which can halt the flow of communication between the components.
• Could you check the LCD and control panel assembly? Please look for signs of physical damage or loose connections on the control panel. If the LCD panel or its backlight is faulty, it may need replacing. Make sure to see if the screen is flickering or showing error codes that could help you narrow down the problem.
• Check the Power Lines: Use a multimeter to check the flex cables that control the panels. If your voltage readings are low or non-existent, it might be a fault on the power lines or distribution circuit.
• Check the Mainboard: If none of the cables or power cables appear loose, the problem still exists. The mainboard itself may be faulty. More precisely, the internal circuit responsible for interfacing with the control panel could be poorly designed, which may necessitate further testing or even a mainboard overhaul.

General Advice
Printer issues, such as the one you're experiencing, can be complicated as they often require detailed hands-on work with your printer's internal parts. We do not assist customers via remote support or repair, though we do offer evaluation and repair at our local diagnostic facility (https://bchtechnologies.com/printer-repair-service). Unfortunately, due to such high demand, we work on a first-come, first-served basis. Therefore, it may be a few weeks before we can diagnose or repair your printer.
Explore our YouTube Channel for more self-help content (https://youtube.com/@bchtechnologies). On the channel's home page, you could search for videos related to your printer problem. I've been creating content for over nine years and have made various troubleshooting videos for different printer issues, so you're almost assured of finding something that fits your situation. YouTube might also recommend relevant lenses from other creators who can help.
Again, thanks for noticing us contacting you. I hope this has helped you fix your printer issue. Please get in touch with us again if you have other questions or need more assistance.