Technical data

B.1 Diagnostic LED Overview
The system uses the eight LEDs on the control panel to indicate the currently
executing test. When power is turned on, all the LEDs light (LED code is
FF(h)), and then display different codes as the devices are tested.
The LED codes are divided into two fields. The left-most four LEDs represent
the device number and the right-most four LEDs represent a substate that the
device test is currently in. LED codes E0h - FFh are reserved for the console.
B.2 LED Error Codes
The eight LEDs can be translated into two hexadecimal or binary digits of the
form:
X X X X Y Y Y Y
7 6 5 4 3 2 1 0
Where:
• X X X X is the device number (binary) currently under test. Use Table 2–3
to match the code from the LEDs to a device.
• Y Y Y Y is the subtest at which the diagnostic hung.
The LEDs can be used for troubleshooting when the console device is
inoperable.
The Model 60 and VLC system LED codes are listed in the following tables.
B–2 Reading the Diagnostic LED Codes