Hitachi VK-U174 Service Manual page 26

Troubleshooting > Trouble Diagnosis
(6) Subject is greatly out-of-focus when zoomed
No
Check the Zoom
switch unit.
Yes
No
IC2507-49 :
1.2-1.6V
Yes
Note: For the item marked #, perform all
#
Data Initialize and
adjust auto focus.
No
Does autofocus
operate normally?
Yes
END
(7) No zoom operation
No
Does focus operate
normally?
Yes
Check the
No
zoom switch unit.
Yes
When power turned
No
on: TL4021 or
IC2507-41 : Pulse
Yes
TL4008 to 4011 or
Yes
IC4001-28, 26, 30,
24 : Pulses
No
No
IC4001-8 : 3V
Yes
No
TL4023 : 6V
Yes
IC4001 faulty
Zoom switch faulty.
D2502 faulty.
C2523 faulty.
R2546 faulty.
the adjustments required when the
unit is data initialized, before
adjustiNo auto focus.
IC2507 faulty.
See "(4) No zoom and
focus operation."
Zoom switch faulty.
Lens faulty.
Check the 3V line
Check the 6V (VM)
line
Circuit No. Circuit Board
1000 to 1099 SP
1100 to 2999 PC
3000 and higher CSR
C h e c k t h e
No
c o n n e c t i o n s o f t h e
l e n s f l a t c a b l e .
Yes
No
C h e c k t h e 3 V l i n e
T L 4 0 0 6 : 3 V
Yes
T L 4 0 2 2 o r
No
I C 2 5 0 7 - 3 0 :
P u l s e
Yes
L e n s f a u l t y .
4 - 7
C o r r e c t t h e
c o n n e c t i o n s
o f t h e f l a t c a b l e .
IC2507 faulty.
R4002 faulty.
Q4001 faulty.