TM 11-6720-242-35
6-8. Removal and Replacement
(5) Remove the four screws (8) securing the
a. General. This paragraph provides direct support
faceplate (7) to the chassis (34). Remove faceplate.
(6) Reverse steps (1) through (5) to install a
removal and replacement procedures for the edge light
new faceplate.
faceplate and the light assembly. Since it is not
c. Removal
and
Replacement
of
Light
necessary to perform a complete disassembly to
A88ssembly.
remove either of these components, the exploded view
(1) Remove connector 4P1 from its
referenced in the procedures should be used as a guide
receptacle (22) on the V/H panel.
only.
b. Removal and Replacement of Faceplate (fig. 6-
(2) Loosen the two captive screws (2)
securing the cover (1). Remove the cover.
5).
(3) Tag and unsolder the leads to the light
(1) Remove connector 4P1 from its
assembly (12).
receptacle (22) on the panel.
(4) Remove the nut (13) and the washer (14)
(2) Loosen the two captive screws (2)
securing the light assembly.
Remove the light
securing the cover (1). Remove the cover.
assembly.
(3) Remove the setscrew (6) securing the
(5) Reverse steps (1) through (4) above to
knob (5).
install a new light assembly
(4) Unscrew the cap on the light assembly
(12).
Section III. GENERAL SUPPORT MAINTENANCE
6-9. Scope
6-10. Troubleshooting
a. General. Troubleshooting the V/H control panel
The maintenance duties assigned to general support
maintenance are listed below together with reference to
at the general support level includes all the techniques
the paragraphs covering specific maintenance functions.
outlined for organizational and direct support
a. Troubleshooting (para 6-10).
maintenance
for
the
camera.
Systematic
b. Voltage and resistance measurements (611).
troubleshooting, which begins with the operational and
c. Calibration (6-12)
sectionalization checks performed at the organizational
d. Disassembly and reassembly (6-13)
level, must be completed by further localizing and
e. General support testing procedures (6-14)
isolating techniques.
b. General Support Troubleshooting Chart
Malfunction
Probable Cause
Corrective Action
Item
1
POWER indicator lamp does
a.
Circuit breaker CB1 defective............. a.
Replace CB1 (pars 6 3).
not light when POWER
b.
Resistor R19 defective ....................... b.
Measure 220 K across R19.
circuit breaker is set to ON
If open or short, replace
R19.
2
No V/H manual signed
a. Secondary winding of T1 open ................ a.
Check continuity of T.1
received at the camera
secondary(terminals 3 and
4). If open replace T1.
b.
Bridge rectifier (CR1 through
b.
Check CR1 through CR4.
CR4) defective.
c.
Emitter follower Q1 open.................... c.
Check Q1, replace if
necessary.
d.
Resistor R20 of R6 open .................... d.
Check resistors, replace if
open.
e.
Switch S2 defective............................ e.
Check continuity of switch.
f.
Filter FLI defective ............................. f.
Check continuity acrosu pins 2
and 2A, 4 and 4A. Replace
if defective (para 6-11).
3
Incorrect V/H signals
a.
V/H calibrate potentiometer R4
a.
Check calibration of potentio-
received at the camera
not set correctly
meter R4 (para 6-12).
b.
Regulator circuit (Q1, Q2, VR1
b.
Measure output of regulator
and CR5) defective
circuit (para 6-1lb). If im-
proper, check circuit com-
ponents.
Change 1 6-6
