1. Initial Checks: Before delving into specific troubleshooting steps, conduct a thorough inspection to ensure all components are correctly installed. Confirm that the printhead replacement was performed according to the manufacturer's guidelines, and no loose connections or disconnected cables are present.

2. Power Cycle the Printer: Initiate the troubleshooting process by performing a power cycle on the Epson 1390. Turn off the printer, unplug it from the power source, and wait for at least 5 minutes. Reconnect the power cable and restart the printer. Observe if the issue persists.

3. Check for Error Messages: Navigate through the printer's control panel or software interface to identify any error messages or codes associated with the red light on the 'tear drop' button and the absence of the green power light. Cross-reference these messages with the printer's manual or online resources to gain insights into potential causes.

4. Printhead Compatibility: Ensure that the replacement printhead is compatible with the Epson 1390 model. Incompatibility issues may lead to malfunctioning and trigger warning lights. Consult the printer's documentation or Epson's official website for a list of compatible printheads.

5. Firmware Update: Outdated firmware can sometimes result in operational issues. Check the manufacturer's website for any available firmware updates for the Epson 1390. Follow the provided instructions to update the firmware, addressing potential compatibility and performance issues.

6. Perform a System Reset: If the issue persists, attempt a system reset. Consult the printer manual or online resources to find specific instructions on how to perform a system reset on the Epson 1390. This process can often rectify configuration or software-related glitches.

7. Contact Technical Support: If all previous steps fail to resolve the issue, reaching out to the manufacturer's technical support is recommended. Provide detailed information about the problem, steps taken for troubleshooting, and any error messages received. Technical support can offer personalized assistance based on the specific situation.

Additional Resources and Support: For more in-depth tutorials and troubleshooting guides, consider checking out our YouTube Channel at https://youtube.com/@bchtechnologies. Stay updated on the latest tech insights by following our Tech blog. If you're in Greensboro, North Carolina, feel free to visit our local support center for hands-on assistance.

By following these troubleshooting steps systematically, users can increase the likelihood of identifying and resolving the issue with the Epson 1390 printer. Remember to stay informed through our online platforms for ongoing tech support and updates.