TM 11-6625-2781-14&P-2
Section VIII
Table 8-4. System Test and Troubleshooting Procedure
TEST
FAULT
PROCEDURE
1. Set POWER switch to ON.
Light not on
Check Display Section
Power lamp on, fan operates.
and/or fan
Proceed to test 2.
inoperative
2. Rotate INPUT ATTENUATION
None of
Check the -12.6 volt supply from
control and observe LOG REF
the lights
Display Section. If voltage is present
LEVEL index lights
illuminate
see Service Sheet 3. If voltage is
not present, check the Display Section
power supply.
Lights operate properly.
Some, but not
Check light bulbs and see Service
Proceed to test 3
all lights
Sheet 3.
illuminate
3. Set Analyzer controls as follows:
SCANNING
See System Test and Troubleshooting
SCAN TIME
light does not
Procedure in 8552 Operating and
PER DIVISION .......................... 5 ms
illuminate
Service Manual. Check power supply
SCAN MODE ................................ ... INT
circuits.
SCAN TRIGGER ......................... AUTO
and observe SCANNING light
Light operates normally.
Proceed to test 4.
4. Adjust Display Section for
Trace does not
See System Test and Troubleshooting
a baseline trace.
appear
Procedure in 8552 Operating and
Service Manual. Check scan amplifier,
Baseline trace is normal.
scan generator and horizontal
Proceed to test 5.
deflection amplifier.
5. Set analyzer controls as follows:
Signal does not
See System Test and Troubleshooting
FREQUENCY ............................ 30 MHz
not appear
Procedure in 8552 Operating and
BANDWIDTH ............................. 10 MHz
on Display
Service Manual. Check calibration
FINE TUNE.............................. centered
Section CRT
oscillator. If calibration oscillator
SCAN WIDTH . .............. PER DIVISION
is operating properly, go to test 6.
SCAN WIDTH
PER DIVISION ....................... 1 MHz
INPUT ATTENUATION................ 10 dB
TUNING STABILIZER...................... ON
RANGE-MHz ................................ 0-110
BASE LINE CLIPPER ...................... ccw
LOG REF LEVEL ........................ 0 dBm
LOG REF LEVEL Vernier ................ ccw
LOG/LINEAR . .............................. LOG
VIDEO FILTER .............................. OFF
SCAN TIME
PER DIVISION ...................... 2 msec
Connect CAL OUTPUT to RF INPUT and
observe display.The 30 MHz signal
should appear close to the center of the
display CRT at a level of -30 dBm. If
signal is correct, proceed to test 7.
8-14
