BBK DK1410SI - Page 58

No voltage output
Each path has no voltage output
Only one path has no voltage output
Find which path has no output
1. Check whether inductor has
open circuit
2. If there is voltage regulator,
check whether it is normal after
changing voltage regulator
Check whether filter capacitor
has electric leakage
Several paths have no voltage output
Check whether
C509, TC508, TC509
has electric leakage
or short circuit
OK
Change corresponding element
1. Check fuse
2. Check bridge circuit rectifier diode
3. Check element on electromagnetic
interference filter circuit
Note
Y
Check
whether cathode
board of D505 has 3.3V
voltage
Change
DV505 and
check whether it is
normal
N
Check
whether R508,
R509, C513, R513 are
normal
Y
Y
N
Change
U503 (TL431)
and check whether it is
normal
Change
U502 (2501)
and check whether it is
normal
Check feedback
loop and other
relevant element
N N
OK
Y
OK
Y
Check
whether cathode
of rectifier diode has
voltage
Whether
it is normal
after changing rectifier
diode
N
N
OK
Y
Y
Y
Check
whether TC501
has 310V voltage
Y
Note
Y
Change corresponding element
Check
whether R502,
C503, D502, R505, C502,
TC502 have short circuit
or electric
leakage
Change
U501 (5L00380)
and check whether it is
normal
Change
U502 (HS817)
and check whether it is
normal
Change
U503 (TL431)
and check whether it is
normal
Change transformer
N N N N
OK
Y
OK
Y
OK
Y
Y
N
17. Troubleshooting process for no voltage output is shown as the following figure 3.3.2.18:
Figure 3.3.2.18 Troubleshooting flow chart for no voltage output
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