TM 11-6130-413-40
Corrective Action
Probable Cause
Malfunction
Item
Check timer switching by starting with the sus-
Defective timer switch contacts.
3
Unit skips from Charge 1 to Charge 2
pected timer set about 10-15 minutes CW from
without discharging; or does not move
the 1 hour mark. Then start the cycle. Turn the
to next phase.
pointer manually very firmly and steadily to the
one hour mark. If the transition is satisfactory,
proceed to do the same thing but this time
"teasen the contacts by hesitating and even re-
versing the motion slightly as the knob is moved
to the end point. If the contact or the cam is worn
out, the resulting contact bounce may cause the
circuit to jump a phase or go into reset.
NOTE
In practice, the discharge timer does not
transfer on timer operation -it either=
EOD before or after the one hour contact.
As a result, its contacts seldom operate at
a time when transition is possible.
4
EOD circuits inoperative.
Check voltage on battery at end of Phase 1 (imme-
All batteries pass discharge test.
diately after PASS light cornea on). If it is less
than 18.05 5% (for 19 cells) or 19 5% (20
cells) then EOD is switching in at too low a volt-
age.
a. Blown output fuse F2 (not the
a. Replace F2.
Batteries do not discharge; or no control
5
problem if unit charges).
of output. (Refer to paragraph 3-4d.)
Replace PCB(A1) and forward to Depot for further
b. Defective circuit board.
repair.
Check procedures; check battery voltage and/or
Operator error or electrical noise
6
Unit stops in middle of a phase
line voltage connections.
or bad connection activating
error detection circuit.
NOTE
If printed board is suspected refer to table 3-1 for normal voltage and readings on a functioning assembly.
Figure 3-1. SCR Waveforms
3-6
