CPU System Overview
2.4 BA440 Enclosure Components
Table 2–6 H7874 Power Supply Switches, Controls, and Indicators
Control/Indicator
Function
AC Present indicator (orange)
Lights when the Power switch is set to on (1), and
the ac voltage is present at the input of the power
supply.
Power switch
The Power switch is used to turn system power on
and off. The off position is indicated by a 0; the on
position is indicated by a 1.
The Power switch also functions as the system
circuit breaker. In the event of a power surge, the
breaker will trip causing the power switch to return
to the off position (0). Turning on the system resets
the circuit breaker. If the circuit breaker trips, wait
one minute before turning the system back on.
DC OK indicator (green)
When the DC OK indicator is lit, the voltages are
within the correct operating range. An unlit DC OK
indicator shows a problem with the power supply.
Fan Failure indicator (amber)
The Fan Failure indicator lights if either of the
two cooling fans stops working. The power supply
will automatically shut down the system as a
precautionary measure when a fan failure is
detected.
Over Temperature indicator
(amber)
The Over Temperature indicator lights if the
system has shut down due to an over temperature
condition.
(continued on next page)
CPU System Overview 2–21
