TM 11-6625-3041-12/TO 33A1-8-908-1
Section I
DESCRIPTION OF CONTROLS AND INDICATORS
2-1. FRONT PANEL CONTROLS, INDICATORS, AND CONNECTORS
Name
Type
Function
ON-OFF
Toggle switch/
Turns on SG-1139 and starts error measure-
circuit breaker
ment. Trips off automatically if overload
occurs.
POWER
Green indicator
Lights when ON-OFF switch is set to ON and
power is applied to SG-1139.
Momentary
LAMP TEST
When pressed, lights all indicators (except
pushbutton switch
POWER) and sets all seven digits in ERRORS
display to 8.
POWER
Red indicator
Lights, together with FAULT indicator, if
SUPPLY
any internal power supply card is defec-
tive.
FAULT
Red indicator
Lights if any internal power supply or logic
card is defective, if timing and data cables
are crossed, or if in LOOPED TIMING mode using
loopback connections with 128-4608 DATA RATE
settings.
