Read Sony KDL-43W780C Service Manual online
16
Troubleshooting
3-1-3. NO POWER: Ayu2L control
No Power
Check STBY_+3.3V
at AYU2L
(H15, H16, H17 pin
C7376)
Look for AC_MON line
at CN9101 pin12/C9131 or
Adapter/ G board failure
NG
NG
Check STBY_+1.0V
at AYU2L
(J15, J16, J17 pin
C7380)
Check Xtal oscillation
X7301
, 32.768kHz
(A23, B23 pin
R7396)
OK
Check AC_MON
at AYU2
(C11 pin C7334)
look for where
STBY_+3.3V
is NG.
look for where
STBY_+1.0V
is NG.
NG
Replace X7301 or Ayu2L
OK
It might be power supply problem
Please refer "DC/DC converter check" sheet.
Look for MAIN_POWER line
at CN9101 pin11
or replace AYU2
NG
Check MAIN_PWR
at AYU2
(C13 pin C7315)
OK
Adapter/
G-board
NG
Check +19.5V(Adapter)
Or +12V(G-Board)
at CN9101 pin21
OK
OK
Check STBY_+1.8V
at AYU2L
(H19 pin
C7374)
look for where
STBY_+1.8V
is NG.
OK
OK
NG
NG
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