Operation waveform for each part
6. SMPS
Is [U4140 : TOP268VG] dam-
aged?
Is [D4142 / D4143 / D4144 /
D4145 / U4140] damaged?
Repair the short circuited area
on the PCB.
Check the damaged parts.
Replace the damaged part.
Replace the damaged part.
Is the fuse [F4140] functioning
properly?
Are there any short circuits
caused by the soldering on the
PCB?
Are any parts damaged?
Replace the [U4140 : TOP268VG
and D4142 / D4143 / D4144 /
D4145].
DC 5V is not output.
NO
NO
NO
YES
YES
YES
YES
YES
YES
1
3
2
OPTION
OPTION
OPTION
OPTION
OPTION
BKT4142
OPTION_2
OPTION
EER2525
T4140
TOP268VG
IC_TOP268VG
U4140
S
V
S
S
X
C
S
S
F
S
D
A
B
C
After primary side rectification
(Caution: High voltage, electric shock)
Primary drain
(Caution: High voltage, electric shock)
After secondary rectifications
A
B
C
A
B
C
SMPS unit
(Unloaded)
Set
Before Servicing
This Unit
Electrical
Mechanical
Repair Information
Updating
78