This section has an
evaluation of the rt.
Section Ill. TROUBLESHOOTING
operational check and troubleshooting flow charts. The operational check is a complete
If passed, the rt can be returned to service. The troubleshooting fIowcharts are used when
the rt fails an operational check step. The troubleshooting flowcharts are used to find the bad module.
When an rt is received for troubleshooting, do the following:
a. Inspect rt for damage. Repair any damage before proceeding.
b. Do the operational check.
c. Do any troubleshooting called for by the operational check.
d. Replace the bad module.
e. Verify the repair by doing all of the operational check.
The troubleshooting procedures are for both AN/ARC-201(V) and AN/ARC-201A(V) radio sets.
But some of the rt/rcu keyboard markings are different. In the troubleshooting procedures, the
AN/ARC-201A(V) marking is given first, followed by the AN/ARC-201(V) marking in paran-
theses. Example: ERF/OFST (SEnd/OFST).
2-23. OPERATIONAL CHECK
The operational check is a series of steps used to evaluate rt operation. It is used both during troubleshooting
and to verify the rt is good after repair.
When testing an RT-1478 or RT-1478A remove its front panel and replace with the RT-1477 front
panel in the maintenance group. Then test the rt as an RT-1477. If the rt passes, the RT-1478 or
RT-1478A front panel is assumed bad. If the rt fails, replace the bad module. When testing and
repair are complete, install a good RT-1478 or RT-1478A front panel. Replace identification plate
to assure proper information, if necessary.
Test Description. Each step checks the response of the rt to an operator action. The steps are numbered so
they can be used for reference on maintenance worksheets. Each step is titled according to the function being
How to Proceed. If normal results are found proceed to the next step. If abnormal results are found, replace the
indicated module or go to the indicated troubleshooting flowchart.
Connect the test setups only when directed and with the power supply turned off. The large
current capacity of the test power supply can cause personal injury. Verify the test setup before
turning the power supply on.
To avoid damage to equipment, always set DC switch on test adapter to OFF before turning
power supply on.
Before setting DC switch on test adapter to ON, always set rt and rcu FUNCTION switches
to STOW or OFF. This applies to the uut, the ref rt, and the ref rcu. Failure to do so
may damage an rt or rcu.
You should not have an rcu connected to J6 of the test adapter. Having an rcu connected may
cause bad test readings or may damage the equipment.