TM 55-4920-414-13&P
Table 4-8. Test BOX Troubleshooting
TROUBLE
PROBABLE CAUSE
REMEDY
No Trim S3 28 vdc voltage
(paragraph 4-23 a. and b.)
No SAS S2 28 vdc voltage
(paragraph 4-23c)
No Boost S1 28 vdc voltage
(paragraph 4-23d)
No SAS Press 28 vdc voltage
(paragraph 4-23e)
No 115 vat, 60 Hz power
(paragraph 4-23a)
CB2, S6, S3, TB1,
Cable Assembly J466R,
J1 Cable Connector
Replace malfunctioning
component associated
with DC power circuit and
(Trim) FO-1.
CB2, S6, S2, TB1,
Replace malfunctioning
Cable Assembly J468R
component associated with DC
power circuit (SAS) FO-1.
CB2, S6, S1, TB1,
Replace malfunctioning
Cable Assembly J469R
component associated with DC
power circuit (Boost) FO-1.
CB2, S6, TB1,
Cable Assembly J467R
CB1, S5
No +15V or -15vdc
CB1, S5, PSI
out of PSI power supply
(paragraph 4-23f)
No +5 vdc out of PS2 power
CB1, S5, PS2
supply
No variable current
indicator on meter Ml
(paragraph 4-23h)
or
Meter Ml has malfunction
PS1, PS2, Ml, AR2
Q1 thru Q4, AR1, S4
R1, and associated resistors
and capacitors on component
board (Al) figures 4-12 and 4-13.
Replace malfunctioning
component associated with DC
power circuit (SAS PRESS)
FO-1.
Replace malfunctioning
component associated with AC
Power circuit FO-1.
Replace malfunctioning
component associated
with AC Power circuit (PSI)
FO-1.
Replace malfunctioning
component associated with AC
power circuit (PS2) FO-1.
Replace malfunctioning
component associated
with meter circuit FO-1 or (A-1)
board as applicable
4-24
