Service manual
• Trouble Shooting Chart (DBOXD0005PAZZ
-----
for
UK)
Problem 1: No voltage appears
at
any
output
terminal.
Is
there
AC
240V
present across C101?
Check
for
AC
cord,
AC
socket,
AC
switch and C101.
Check
for
F101
Ok
andT101.
Problem 2:
-5V
is
not
developed.
Is there
AC
10V
present across the
orange
lead?
Check
for
T101.
Is there DC
11
V
present across
C201 ?
No
Check
for
F201,
0201
and C201.
No
Check
for
IC1,
R201,
VR201
and C202.
Is
there DC
-5V
present across C202?
Problem 3: +12V
is
not
developed.
Is there
AC
20V
present across
the
yellow
lead?
No
Ok
Is there
DC
23V
present across C301 ?
Problem 4: +5V
is
not
developed.
Is there
AC
20V
present across the
yellow
lead?
No
Check
for
T1 01.
Is
there DC
23V
present across C301?
No
Check
for
0301
and
0302
(short-circuit
after
rectification)
.
Is
there DC
12V
present across C404?
No
Check
for
L201 and
Ok
F202.
No
Check
for
IC2
and
its peripheral parts.
Check
for
output
switching
circuit.
Leave
R403
be
open: does there
appear
0.3Vp,;ll
pulse
at
pin
~
of
IC2?
Check
for
L402
Ok
and
F401.
No
Check
for
0301
and
0302
(short-circuit
after
rectifi-
cation).
Is there DC
5V
present
across C507?
-15-
No
Ok
Check
for
IC3 and its
peripheral parts.
Leave R
503
be
open:
does there appear
~Vp-p
pulse
at
pin
~
of
IC3?
Check
for
L503
and
F501.
MZ
80K