HP 2300d Service Manual - Page 187

Troubleshooting the control-panel display Try to fix common problems before replacing the control-panel display. No display. If power-on is normal, but the control panel does not work, then try disconnecting and then reconnecting the control panel connectors. Poor display. If the control panel is working, but the display is illegible or shows poor contrast, then check the contrast label (callout 1) on the back of the control panel. 12 Figure 105. Control panel contrast label The contrast label contains a number that corresponds to an optimum display-brightness setting. Change the brightness setting in the control-panel menus to the number shown on the label (see page 65). If the control panel display is so poor that it is impossible to use the control-panel menus, then change the brightness after using a "bootup" key-sequence. To use the "bootup" key-sequence 1 Turn the printer off. 2 Hold the BACK button down and turn on the printer. Continue to hold the BACK button until all three LEDs are lit. 3 Press (SELECT) to enter the control panel contrast settings. 4 Press (SELECT) to advance to the LCD set. 5 Press (SELECT) to advance to the brightness settings. 6 Use the (UP arrow) or (DOWN arrow) to scroll through the numbered settings. 7 Press (SELECT) to save the setting. ENWW Chapter 7 Troubleshooting 185