TM 55-4920-413-13&P
Section IV. MAINTENANCE (AVUM)
4-6. Scope.
The scope of corrective maintenance is the replacement of
knobs, fuses, and indicator lamps and lenses, and the cable
assemblies.
4-7. Fuse Replacement.
a.
b.
c.
d.
4-8.
Make certain INPUT POWER switch is OFF.
Disconnect LTS/VIDS from power source.
Unscrew fuse holder cap and remove fuse.
Insert new fuse and replace fuse holder cap.
Knob Replacement.
a. Loosen setscrew holding knob to shaft.
b. Slide knob off shaft.
c. Place new knob on shaft, making certain knob is fully on
shaft and indexed correctly.
d. Tighten setscrew.
4-9. Indicator Lamp Replacement.
NOTE
This applies to the seven warning lamps only.
a. Make certain INPUT POWER switch is OFF.
b. Remove lens cover.
c. Remove lamp,
d. Install new lamp,
e. Replace lens cover.
4-10. Cable Assemblies.
.
Remove cable assembly from LTS case and ship to higher
maintenance.
4-11. Lubrication.
None is required.
Section V. MAINTENANCE: Authorized REPAIR AND REPLACEMENT OF PARTS (ATST)
NOTE
Authorized repair of the IDSL Test Set by Avia-
tion Intermediate Maintenance (ATST) personnel
is indicated in Appendix B, Maintenance Alloca-
tion Chart.
NOTE
Aviation Intermediate Maintenance (ATST) will
perform only the authorized maintenance which in-
cludes replacement and repair of components and
end items which can be accomplished efficiently
with available skills, tools, and test equipment.
Evacuate, circuit boards, components and end
items beyond capability of ATST to the Depot.
cuits troubleshooting schematics FO-1 through
FO-5. Do not replace circuit board if repair can be
accomplished by authorized replacement of com-
ponents on board.
NOTE
Remove Keying Plug from circuit boards before
inserting extender board in assembly connector
(Plugs in each circuit board). Be sure to reinstall
keying plugs after maintenance has been
completed.
NOTE
Place INPUT POWER switch OFF before remov-
Perform Paras 4-12 and 4-13 as directed by
ing or installing printer circuit boards and
Troubleshooting Tables 4-5 through 4-17 and cir-
connections.
4-3
