TM 11 5895-1096-40
3-11. Troubleshooting Tables
It may be necessary to partially
a. General. There are two troubleshooting tables
remove the fungicide coating to
for the TS-3566/GRA-114: table 3-5 enables you to
insure good electrical connections.
troubleshoot the main assembly and probe amplifier
while table 3-6 enables you to troubleshoot the encode
b. Main Assembly and Probe Amplifier. Follow the
generator circuit card.
procedures in table 3-5 to determine the corrective action
for repair of the main assembly and probe amplifier.
NOTES
c. Encode Generator Circuit Card. Follow the
All troubleshooting procedures on
procedures in table 3-6 to determine the corrective action
the test set are performed with the
for repair of the encode generator circuit card.
test set disassembled (para 3-16).
Table 3-5. Main Assembly and Probe Amplifier Troubleshooting
Malfunction
Probable Cause
Corrective Action
1.POWER indicator does not light when POWER
a
Defective fuse assembly
a
Disconnect test set from 120 VAC source.
switch is set to ON
Using Multimeter AN/USM-223, check for con-
tinuity of AC input circuit.
(1) If CORRECT, go to step e.
(2) If INCORRECT, repair wiring/replace defec
tive component.
b
Defective indicator assembly,
b
Perform a above.
c
Defective POWER switch S7
c
Perform a above.
d
Defective input power cord
d
Perform a above.
e
Defective transformer TI
e
Replace.
2 No CODE OUT or SYNC OUT signals generated
Defective encode generator circuit card
Go to table 3-6, Malfunction 1.
3 Erratic or no CODE OUT signal generated; SYNC
a
Defective code output wiring
a
Disconnect test set from 120 VAC source.
OUT normal
Using Multimeter AN/USM-223, check for con-
tinuity
(1) If CORRECT, go to table 3-6, Malfunction 2.
(2) If INCORRECT, repair wiring/replace defective
component.
b
Defective CODE SELECTOR
b
Perform a above.
switches.
c
Defective PHASE, MODULA
c
Perform a above.
TION, or MESSAGE switch.
4 Erratic or no SYNC OUT signal generated
Defective SYNC OUT wiring or
Disconnect test set from 120 VAC source Using
CODE OUT normal
BNC connector J3
Multimeter AN/USM-223, check for continuity from
center conductor of SYNC OUT connector J3
to PI-20 on encode generator circuit card.
(1) If CORRECT, go to table 3-6, Malfunction 3.
(2) If INCORRECT, repair wiring/replace defective
connector.
5 Signal not present at 19.25 MHz OUT connector J4
a
Defective cable WI to oscillo
a Replace both Wl cables.
on test set when using external probe amplifier
scope or WI to probe amplifier.
assembly.
b
Defective DC supply output to
b Using Multimeter AN/USM-223, check for + 12
probe amplifier
VDC nominal at center conductor of AMPL
PROBE connector J5.
(1) If CORRECT, go to step c.
(2) If INCORRECT, disconnect test set from 120
VAC source Using Multimeter AN/USM-223,
check for continuity from center conductor of
AMPL PROBE connector J5 to P2 on encode
generator circuit card.
c
Defective 19.25 MHz output
c. Disconnect test set from 120 VAC source
Using
connector on test set
Multimeter AN/USM-223, check for continuity
from center conductor of 19.25 MHz OUT connector
J4 to P3 on encode generator circuit card.
(1) If CORRECT, check C9 on encode generator
circuit card.
3-10
