ARMY TM 5-6675-238-14
MARINE CORPS TM 08839A-14/1
Table 8-8. Tape Reader Testing and Troubleshooting Procedure
Malfunction indication/
Test procedure
Normal indication
corrective action
1. PRELIMINARY TESTS.
None of the circuit cards are keyed; therefore, any card will fit into any card slot. Refer to side of card cage for
proper orientation of cards. Failure to comply may result in damage to the equipment.
NOTE
This procedure is for tape reader, part no. 877406-1.
At any time during testing when resistance measurements are to be made, or when cards and card extenders are to
be removed or installed, remove power to the tape reader by pressing the SPU ON switch-indicator to off. When
ready to resume testing, reapply power to the tape reader by pressing the SPU ON switch-indicator to on. Any
switch-indicator that is on (REVERSE MEMORY LOAD) should be pressed off and then back on again (function
needs to be restored after power is cycled). Resume testing.
la. Turn two reels, two tape sens-
Reels, tape sensing arms, and step- Replace defective part
ing arms, and stepping motor
ping motor sprocket move
sprocket by hand
freely
lb. Set tape reader SPOOLING
switch to DISABLE
lc. Press SPU ON switch-indica- Reels do not rotate
If reels rotate, replace S1
tor to on
ld. Observe tape reader TIME TIME HOURS meter is operating
HOURS meter
by observation of comma oscil-
lation
le. Set tape reader SPOOLING The supply (left) reel rotates coun-
switch to ENABLE
terclockwise
The take-up (right) reel rotates
clockwise
All nine bulbs on lamp assembly
DS1 light
The stepping motor sprocket does
not rotate freely (cannot be
turned by hand)
If meter is not operating, check + 28V
fuse. If fuse is good, or keeps blowing
out when replaced, check the meter
wiring
If the wiring is good, replace meter
If all four indications fail, check 115-
VAC fuse
If fuse is good, perform test 2; if fuse
keeps blowing, check for shorts (see
FO-19)
If both reel tests fail, perform tests 2 and
3. If the supply reel test fails, perform
tests 2 and 3.1
If the take-up reel test fails, perform
tests 2 and 3.2
If no bulbs on lamp assembly DS1 light,
check R1. If R1 is good or if at least
one bulb lights, but others (one to
eight), do not light, replace lamp as-
sembly DS1
If stepping motor sprocket turns easily
by hand, perform tests 2 and 4. If tests
pass, replace B1
8-64.2
Change 1
