Technical data

Troubleshooting
Firmware Selftest Failures
4-8
Firmware Selftest Failures
Two methods are used by the firmware to provide diagnostic information: the LEDs on the
board computer’s front panel and ASCII encoded chassis codes which are output through
the RS-232 (A) port.
Interpreting the Front Panel LEDs
The Model 743 provides two LEDs, located to the left and right of the reset switch, as
shown in Figure 4-1. The red LED is labeled SYSFAIL and the green LED is labeled
POWER.
Figure 4-1 Model 743 LED Location
Red LED
Reset Switch
RS232 (A)
Green LED