Simrad RA771UA, Instruction Manual

Page: 28 / 46

i o n
Antenna d r i v i n g
p i n i o n - g e a r
mechanism
C l e a n i n g
CRT
HV
p a r t s
C l e a n i n g
p r i n t e d c i r c u i t
b o a r d s
C o n n e c t o r s
Screw
w i t h i n
d i s p l a y u n i t
l a i n t e n a n c e
e v e r y 6
1 2 months
P r o c e d u r e
s e l e c t e d q u a l i t y
o n a l l s u r f a c e s o f
d r i v i n g
gear
u s i n g
s u i t a b l e s p a t u l a .
t h e a n o d e cap o f t h e
i t s
v i c i n i t y , a n d
HV
l e a d s w i t h a d r y c l o t h .
Note t h a t
HV
of a b o u t 1 0
i s
a p p l i e d t o t h e
C R T .
NEVER
i n s p e c t u n t i l you a r e
SURE t h e r a d a r power s o u r c e
i s
t u r n e d OFF. High s t a t i c
v o l t a g e
may be r e t a i n e d i n
t h e CRT h i g h - v o l t a g e
c i r c u i t
and t h e C R T .
D i s c h a r g e h i g h
s t a t i c
v o l t a g e s t o g r o u n d by u s i n g
an i n s u l a t e d c o n d u c t o r
b e f o r e m a i n t e n a n c e .
I f
s o o t ,
d i r t , a n d d u s t
a c c u m u l a t e
on
mounted components,
u n e x p e c t e d t r o u b l e may
r e s u l t . C l e a n u s i n g
a
vacuum c l e a n e r w i t h
a
s o f t
b r u s h .
Check
a l l
c o n n e c t o r s f o r
p o o r
c o n t a c t .
I f p r e s e n t ,
r e p a i r
o r
replace i t .
Check a l l f a b r i c a t i o n
o r
mounting
screws
i n s i d e
d i s p l a y u n i t f o r l o o s e n e s s .
I f
l o o s e ,
r e - t i g h t e n w i t h
s c r e w d r i v e r .
4.2 Checking
Fuses
and V o l t a g e s
Check f u s e s a n d v o l t a g e s on t h e power s u p p l y u n i t
when any CHECK
i t e m
i n SETUP mode shows t h e r a d a r
i s
f a u l t y , o r c h e c k f u n c t i o n i t s e l f d o e s n o t w o r k . F u s e s
blown up show t h a t some c a u s e s of m a l f u n c t i o n h a v e e x i s t e d
i n
t h e r a d a r s u c h a s s h o r t i n g c i r c u i t s . Table b e l o w
l i s t s
f u s e s a n d v o l t a g e s .
4-2