Epson DM-M820, Technical Reference Manual, Page: 202 / 324

8-12 Troubleshooting Rev. I
LCD Display Screen Too Dark, Too Bright or Cannot Be Adjusted
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Follow the procedures below.
1. Confirm whether adjusting the brightness level on the LCD solves the problem.
2. Confirm whether replacing the switch cable assembly solves the problem.
3. Confirm whether replacing the LCD circuit board solves the problem.
4. Confirm whether replacing the inverter board solves the problem.
5. Confirm whether replacing the LCD solves the problem.
Other Display Problems
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If any of the following problems occur, check the monitor signal connection/cable, monitor,
and system board.
• Incorrect colors.
• No high intensity.
• Missing, broken, or incorrect characters.
• Destroyed image.
• Unreadable monitor.
Touch Panel Faults
Note:
If the keyboard or mouse does not function, refer to the problems described in the section titled
“System Unable to Start” on page 8-3.
Touch Panel Does Not Function
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Follow the procedures below.
1. Confirm whether the touch panel is connected to the COM1 or COM2.
• You must confirm whether to use the COM1 or COM2 for the touch panel.
2. Check the external connectors.
3. Check the touch panel driver settings. For example, check the IRQ and I/O address for
each port.
4. Confirm whether calibrating the touch panel solves the problem. (Refer to Chapter 7.)
5. Reinstall the touch panel driver after uninstalling it.