Table of Contents
Advertisement
Power Supply Condition Indicators
Three LEDs indicate the condition of the three console
power supply voltages from the load frame: +5 Vd.c.,
+15 Vd.c. and -15 Vd.c. Each LED is lit when its respec-
tive power supply voltage is present, and it is off if that
power supply has failed.
If the Self Test does not function, this may indicate a
loss of the +5 V supply, so check its LED first.
If a ±15 V supply fails, the Self Test result will show a
failure of one or more sections of the circuit board, and
the backlit status/fault indicators on the Main Panel will
not light.
If an LED is dimly lit, this indicates a drop in voltage
level from its power supply. The intensity of an LED is a
coarse indicator and it will not be apparent for a small
drop in voltage level.
Green Test LEDs
Each circuit section which has its input and output under
control by the CPU has a green TEST LED. These
LEDs are on during the first part of the Self Test and off
during the second part. When the Self Test concludes, a
lit TEST LED indicates its section is good; if the LED is
not lit, the section did not pass the test. During normal
operation all green TEST LEDs are lit. However, some
flickering may be seen on certain green LEDs which is
due to software telemetry. For example, the flicker of the
green LED on the CPU section is caused by system inter-
rupt response. Figure 8-2 shows a closeup view of the
details of the main console indicators.
Rear Panel Indicators
8-11
Advertisement
Table of Contents
