TM 11-5820-890-30-4
4-66. REPLACEMENT OF ZENER DIODE VR1/VR2.
Tools:
Flat tip screwdriver
Torque screwdriver
Soldering kit
Cross tip screwdriver
Expendable Supplies:
Cotton swabs
Solder
Alcohol
References:
Paragraph 4-62 for removal and installation of circuit breaker CB1.
ITEM
ACTION
REMARKS
REMOVAL
a.
b.
c.
d.
Mounting adapter
Side access cover (16)
Mounting bracket (20)
Zener diode
VR1/VR2 (24)
INSTALLATION
e. Zener diode
VR1/VR2 (24)
f. Mounting bracket (20)
g. Side access
cover (16)
Set on work surface with left side
toward you.
Remove and retain.
Using cross tip screwdriver, remove and
retain two screws (21), lockwashers, and
fiat washers securing mounting bracket
(20) to power control chassis. Remove
mounting bracket to allow for desoldering.
Note polarity. Using soldering kit, desolder
defective Zener diode VR1/VR2 (24) from
terminal studs (25) on mounting bracket
(20). Remove and discard defective Zener
diode VR1/VR2 (24).
Note polarity. Using soldering kit, solder
replacement diode to terminal studs
(25) on mounting bracket (20).
Position mounting bracket to power con-
trol chassis. Using cross tip screwdriver,
install two retained screws (21), lock-
washers, and flat washers securing
mounting bracket (20) to power control
chassis.
Install.
Refer to paragraph 4-62
for removal procedures.
See figure 4-19.
Before and after soldering,
clean leads with alcohol
and cotton swabs.
These were removed in
step c.
See figure 4-14. This was
removed in step b.
Refer to paragraph 4-62 for
installation procedures.
4-180
