Specifications

TM 11-5820-670-30
2-26. TROUBLESHOOTING CHARTS. (CONT)
CHART 2-24
Control Unit Troubleshooting
(Sheet 2 of 12)
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
5. Speaker noise present/not present (SQUELCH switch at CARR).
Check for short circuit between main connector J9101 pin V and ground. (See FO-13.)
Replace switch S9106 (para 2-78).
6. Speaker noise not present (SQUELCH switch at DIS).
Check for infinite resistance between main connector J9101 pin V and ground. (See
FO-13.)
Repair wiring or replace S9105 (para 2-81) or squelch switch S9106
(para 2-78).
7. Gearbox kHz indicator does not track with frequency selected.
Check continuity of the kHz tuning control lines to ground. (See table on sh 9, FO-13
and FO-21.) Also see resistance tables sh 4.
Repair wiring or replace frequency selector switches S9103 (para 2-80)
or S9104 (para 2-80).
8. Gearbox MHz indicator does not track with frequency selected.
Check continuity of the MHz tuning control lines to ground. (See table on sh 11, FO-13
and FO-21.) Also see resistance tables sh 4.
Repair wiring or replace frequency selector switches S9101 (para 2-83)
or S9104 (para 2-80).
9. Antenna coupler simulator test failure.
Check continuity of the MHz tuning control lines to ground. (See table on sh 10,
FO-13 and FO-21.) Also see resistance tables sh 4.
Repair wiring or replace frequency selector switches S9101 (para 2-83)
or S9102 (para 2-84).
2-115