TM 11-6720-242-35
(3) Troubleshooting control panel.
Malfunction
Probable Cause
Corrective Action
Item
1
Extra picture circuit does not
EXTRA PICTURE switch S5 .................. Check switch operation and replace
function
if found faulty (fig. 6 11).
2
No V/H input to scaling
CAMERA SEL switch S4 ....................... Check switch operation and replace if
network on control board
necessary.
assembly.
3
No +28 vdc or 115 vac power POWER switch S1................................. Check switch operation and replace
input to interface board
if necessary.
assembly.
4
Camera does not operate in
OPERATE switch S2 ............................. Check switch operation and replace
autocycle mode
if necessary.
5
No V/H voltage ......................... V/H SEL switch S3................................. Check switch operation and replace
if necessary.
(4) Troubleshooting magazine.
Malfunction
Probable Cause
Corrective Action
Item
1
Scratches on film ...................... a.
Burs on pressure plate.................. a. Replace pressure plate assembly
b.
Burs on film guides....................... b. Replace pressure roller assembly
2
Film disengages from
a.
Spring in keeper block exhausted, a. Install new spring in keeper
sprockets
damaged or left out
b.
Keeper rollers damaged ............... b. Replace keeper block assembly
(para 341).
3
Adas image out of focus
a.
Roller follower damaged............... a. Replace pressure roller assembly
on film
b.
Adas pressure plate twisted out b. Turn adas pressure plate until
of position
4
Film does not advance
a.
Roller damaged or does not rotatea. Replace pressure roller assembly
smoothly
smoothly
b.
Film guides bent or
b. Replace pressure roller assembly
damaged
5
Film spool cannot be properly a. Damaged pivot on spindle
a. Replace affected spindle assembly
attached to spindle
assembly
(para3-43).
b.
Damaged slot on film spool .......... b. Replace film spool (par 844).
6
Film does not take up
Bent or damaged film spool ................... Replace film spool (para 344).
3-5. Signal Substitution Tests
(2) Set the test set. switch to position 1 an(
a. General. The special test fixtures described in
check for a meter reading of +15 +1 vdc between pins
2M and 1C.
paragraph 33 provide necessary signal substitutions for
(3) With the test set switch set to position 1
testing a power supply board assembly and a scan heat
check for a meter reading of -165+1 vdc between pins
sink assembly.
b. Testing Power Supply Assembly. Insert the
2Z and 1C.
(4) Reset test set switch to position 2 and
power supply board assembly in the special test fixture
check for a meter reading of + 15 + 1 vdc between pins
shown in figure 3-1. A vacuum tube voltmeter will be
2M and 1C.
needed.
(5) With the test switch set to position 2,
NOTES
check for a meter reading of -15 +1 vdc between pins Z
1. When the designated value or condition of
and 1Z.
(6) Check for a meter reading of 6+0.6 vac
a test is not obtained, trace the
between pine 2D and 1C.
malfunctioning circuit in figure 6-17 to
(7) Check for a meter reading of 29 + 8 vac
isolate the faulty part or assembly for
between pins 2J and 1C.
replacement.
(8) Check for a meter reading of +21 8S vdc
2. The pins designated in the following
between pins 1Y and 1C. Then check for a maximum
procedure refer to the test fixture.
meter reading of 4 vac, rms, between the same pins.
(1) Set the power on.
Change 1 3-5