TEST OR INSPECTION
Check wiring from P1 to S2. Check relay K1 and A1 PCB. Repair wiring/replace defective component.
g. Remove locking plate and set system selector switch to AN/TTC-38. Using multimeter, check for +4.9 to 5.5 Vdc at
P1-3 and P1-4 leads on test cable.
Check wiring from P1 to A1 PCB. Check S2. Repair wiring/replace defective component.
h. Set system selector switch S2 to AN/TYC-39; replace locking plate and hardware. Set multimeter for resistance
measurement and connect to P1-3 and P1-4 on test cable. Connect voltmeter to TP1 and TP4 on front panel. Set variable
load RANGE switch to 180A and increase current loading until voltage on voltmeter decreases. Observe that FAULT
lamp is lighted and multimeter indicates open circuit. Voltmeter reading should be+2.5 to 4.75 Vdc.
Check wiring from S1 to J2-3 on A1 PCB. Check Q3, Q4, and associated circuitry (voltage regulator check).
Check Q11, U7, and associated circuitry ((UV/OV) detection circuit). Repair wiring/replace defective component.
i. Adjust variable load to 75A, and momentarily push in short circuit button. Observe current of 10 to 45A on meter of
variable load. Upon release of short circuit button, observe voltmeter reading of +4.9 to 5.1 Vdc, and 75A indication on
meter of variable load.
Check U2, U4, Q11, and associated components. Check T1 on A2 PCB. Replace defective component.
Section Ill. MAINTENANCE PROCEDURES
2-6. Maintenance Functions
General support maintenance includes all the proce-
dures listed in the maintenance allocation chart
Do not perform needless disassembly of
(MAC) and instructions applicable to testing, evalu-
equipment for the purpose of cleaning.
ating and determining the serviceability of the con-
Clean the equipment only to the extent
required for serviceability.
verter. When lower level maintenance reports a fault,
a. Exterior Surfaces.
general support will verify the fault and determine
(1) Remove loose dirt or dust from outside sur-
the extent of testing, repair, modification, or replace-
ment necessary to make the equipment serviceable.
faces of case and front panel using lint-free cloth
(item 5, appx B) and/or soft bristled brush (item 2,
2-7. Preliminary Maintenance Procedures
a. Operational Check. After repairs have been
made to the converter, it should be ready for return
Adequate ventilation should be provided
to service. To verify its condition, refer to section IV
while using TRICHLOROTRIFLUORO-
of this chapter.
ETHANE. Prolonged breathing of vapor
b. Inspection of Installed Items. Inspection in-
should be avoided. The solvent should not
cludes, but is not limited to the following:
be used near heat or open flame; the prod-
(1) Preliminary inspection.
ucts of decomposition are toxic and irritat-
(a) A check of maintenance forms and records
ing. Since TRICHLOROTRIFLUORO-
attached to the equipment.
ETHANE dissolves natural oils, pro-
(b) A check of DA Pam 310-1 for any modifi-
longed contact should be avoided. When
cation work order (MWO) pertaining to the con-
necessary, use gloves which the solvent
cannot penetrate. If the solvent is taken
(c) A visual inspection of the converter for
internally, consult a physician immedia-
compliance with all MWO'S.
(d) A listing of outstanding MWO'S on DA
(2) Remove ground-in dirt or grease using lint-
free cloth (item 5, appx B) dampened (not wet) with
(2) Visual inspection.
(a) Exterior surfaces. Inspect exterior surfaces
cleaning compound (item 6, appx B).
for obvious signs of damage. Check metal surfaces
(3) Rinse cleaned areas with clean water and al-
low to dry.
for signs of rust and corrosion.
b. Blower Screen. Remove dust and dirt from
(b) Interior surfaces. Inspect for broken con-
screen using soft bristled brush (item 2, appx B).
nections, improperly seated semiconductors, dam-
aged or improperly installed circuit boards and heat-