Troubleshooting & Maintenance
Front Panel Problems
4-15
Front Panel Problems
LCD not lit
1. Check the LCD brightness and contrast potentiometers on the rear panel. Turn the pots to
see if there is any change.
2. Check the
fl
at ribbon cable from the J304 on the Connector Board. Disconnect and reseat
the cable.
3. Check the cable and solder connections from the LCD to J203-1 and J203-2 on the Front
Panel Board.
4. Refer to the Front Panel Board schematics and check the signal path.
LCD lit, no characters
1. Place the PC3x upside down on a
fl
at protected surface.
2. Remove the seven screws that secure the access panel and set it safely aside.
3. Check the stranded wire cable at the J5 location on the Engine Board. Be sure it is seated
properly. If necessary, disconnect and reseat it.
4. Check the
fl
at ribbon cable at J15 on the Engine Board. Be sure it is seated properly. If
necessary, disconnect and reseat it.
5. Open the unit.
6. Check solder connections on the LCD and Engine Boards.
7. Refer to the Engine Board schematics, see page 6-8 in Chapter 6. Check the LCD_CONT
signal path.
8. Refer to the Connector Board schematics, see page 6-14 in Chapter 6. Trace the contrast
signal from Q4. It should be in the range of -7V to -10V depending on the Contrast control
setting.
Buttons, Sliders or Controllers not working
1. Run the Scanner Tests. If the tests pass, the problem is likely the result of a setting in the
Control Setup. Perform a Hard Reset to the unit or refer to the Control Setup sections in
the
Getting Started Guide
.
2. Refer to the Interconnect Diagram.
3. Check all related cables. Disconnect and reseat the cables.
4. Check the solder connections at the connectors.
5. Check front panel ribbon cable(s).
6. Refer to the Connector Board schematics and check U1, IC Scanner M38869, for signal
activity.
7. Check for the presence of +5V +/-5% on the Ring connection to either Continuous Control
Pedal jack.
