VSX-LX50
75
5
6
7
8
5
6
7
8
C
D
F
A
B
E
7. DISASSEMBLY
1.
Before
t
h
e
Power
Amp
Block
is
removed
Note
1:
Even
if
the
unit
shown
in
the
photos
and
illustrations
in
this
manual
may
differ
from
your
product,
the
procedures
described
here
are
common.
Note
2:
For
performing
the
diagnosis
shown
below,
the
following
j
igs
for
service
is
re
q
uired:
•
11P
board
to
board
e
x
tension
j
ig
cable
(GGD1482)
•
13P
board
to
board
e
x
tension
j
ig
cable
(GGD1483)
•
15P
board
to
board
e
x
tension
j
ig
cable
(GGD1484)
•
21P
board
to
board
e
x
tension
j
ig
cable
(GGD1485)
2
Discharge
C3257
and
C3258
on
the
TRANS
2-1
Assy.
Note:
For
discharging,
use
a
load
of
100
Ω
,
3W
or
more,
to
protect
the
IC
protectors.
Do
NOT
discharge
instantly
by
short-circuiting.
3
Check
that
the
voltage
between
the
electrodes
of
each
C3257
and
C3258
is
1V
or
less.
4
Reassembling
the
Power
Amp
Block.
1
Unplug
the
AC
power
cord.
Before
the
Power
Amp
Block
is
removed,
discharge
C3257
and
C3258
on
the
TRANS
2-1
Assy,
as
indicated
below.
If
you
don
'
t,
the
IC
protectors
(IC3351
and
IC3352)
on
the
VH
TR
Assy
may
be
open,
and
DC
voltage
may
be
generated
at
the
power
amplifier
output,
which
will
result
in
"AMP
ERR."
[Procedure]
IC3252
C3254
C3260
C3259
R3251
3251
R3256
R3254
C3257
C3258
Q3253
Q3253
D3266
C3256
D3265
Q3252
Q3252
D3264
D3262
D3260
D3258
D3256
D3254
UDZS12(B)
UDZS6R8(B)
UDZS8R2(B)
7A
AEK7021
470/100
STBY
STBY
MUF
(1/4W)
47
51048-0600
4.7k
LMF
(1W)
3.3k
(1/2W)
LMF
220/100
220/100
UMD2N
UMD2N
13(B)
100/63
13(B)
UMD2N
UMD2N
2
1
3
6
5
4
-65V
VHb
27
VLb
26
25
-VH
-C
-B
+C
+VH
+B
-56V
+56V
TRANS
2-1
ASSY
To
VH
TR
ASSY
S
TRANS
2-1
ASSY
S
C3258
C3257
