Installation guide

Troubleshooting
Getting Started with Troubleshooting
1-9
ILT3 Front Panel Display Troubleshooting
The Front Panel Display consists of the following four assemblies:
•A1 Keyboard
• A2 Display (640 x 320 pixel liquid crystal display)
• A3 Front Panel Auxilary Board
•A4 Inverter
The A1 Keyboard contains the front panel hardkeys and softkeys, the power on/off switch along with the
standby LED, and the power-on LED. The eight LCD data lines for the A2 Display are routed through the A3
Front Panel Auxilary Board; the A12 CPU controls these eight LCD data lines.
The A4 Inverter turns the A2 Display on and off using control lines routed through the A3 Front Panel
Auxilary Board, which originate on the A12 CPU. The A4 Inverter is used to convert a +5.2 Vdc signal into a
40 kHz 290 Vac signal (approximately); this ac signal is then used to drive the A2 Display.
A2 Display Contrast and Brightness Controls
There are two contrast hardkeys below the A2 Display. The left up-arrow key increases the contrast while the
right down-arrow key decreases the contrast.
The A2 Display brightness can be adjusted from 50 (high brightness) to 1 (low brightness) using the RPG,
arrow keys, or the numeric keypad.
Softkey Location:
Utility > Display > Brightness
A2 Display Tests
There are two screen tests for the A2 Display: the Black Pixel Screen Test and the White Pixel Screen Test.
The Black Pixel Screen Test turns the display dark and the White Pixel Screen Test turns the display bright.
To exit either test, press any front panel key.
Softkey Location:
Utility > Display > More (1 or 2)