BBK DK1410SI - Page 57

P+28V voltage trouble
+28V voltage is on high
or low side
Check
whether pin 1
of U505 (KAIM0880)
has been changed
into 310V
Check
whether D510,
D511, D502 is normal
Check R520, R521, C520
Check
whether Tc515,
TC516, TC517, C523 has
electric leakage
Change
Check whether TC501,
bridge rectifier module
BD501 is normal
Change
Change
U507 (Tl431)
and check whether it
is normal
OK
Change
U506 (Hs817)
and check whether it
is normal
Change
U505 (KAIM0880)
and check whether it
is normal
Check power supply circuit
and absorption circuit on
pin 3 of U505
N
OK
Y
OK
Y
Y
Y
Y
N
N
N
Y
N
Y
N
OK
Y
N
+28V voltage has no output
Check
whether cathode
of D510 or D511 has
28V voltage
output
Check
whether pin 1
of U505 has 310V
voltage
1. Check whether TC508 is normal.
2. Check whether BD501 is normal.
3. Check electromagnetic
interference filtering circuit
and fuse
Check whether L506
has open circuit
1. Change
D510, D511 and
check whether they are
normal 2. Change D502
and check whether
it is normal
Change
U505 (KAIM0880)
and check whether it
is normal
Change
U506 (HS817)
and check whether it
is normal
Change
U507 (Tl431)
and check whether it
is normal
1. Check power supply
circuit on pin 3 of U505
2. Check transformer
Y
OK
OK
OK
Y
Y
N
N
Y
Y
N N N
N
Change
16. Troubleshooting process for P+28V voltage is shown as the following figure 3.3.2.17:
Figure 3.3.2.17 Troubleshooting flow chart for P+28V voltage
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