Panasonic VIERA 50 Series - Trouble Shooting Power LED Blink Errors (4 Blinks); LED 4 times blink < 42” SD (TH-42 PD50 U) >; Power Supply and Protection Circuit; Check Point Location

Trouble Shooting Power LED Blink Trouble
LED 4
times
blink<
42”
SD (TH-42PD50U)
>
Trouble
Mode and
Defective Board
Trouble Mode
Defective Board (Possibility)
Power SOS =Vsus,
5V
down P
,
SC, SS, D, SC,SU
Board
(
P
>
SC, SS,
D,
SU, SD)
How
to
find the defective board
^
No (VSUS NG)
^
^
Disconnect
SC2
and
SS1
1
..Power SW ON.
"VSUS output at P2’s 1 or
2
pin
before Shutdown ?
<
Power SW ON.
-VSUS(*1) output
N
at P2’s 1 or
2
pin
x
before Shutdown ?
No^
.
>
»Ip Boardl
in
i 1
Yes (Vlow NG)
Power SW ON.
/5V output
^at P25’s 7 or
9
pin
before Shutdown ?
j
Yes
|P Boardl
No(5V NG)
Yes
/s.
Connect SC2.
Disconnect SS11.
L
XPower SW ON.
VSUS output at SC2’s 1 or
2
pin
before Shutdown ?
^
Yes
|SS
Boardl
No
Disconnect
SU and SD from SC
(
After Power SW ON,
Power comes up ?
>
2
).
No
Yes
(
Su|>r SD NG)
Connect
SU
to
SC.
SC Board
No (D or P or
C
or Panel NG)
No (Por D NG)
Disconnect SD from SC(*2).
After Power SW ON
Power comes
up
?
Yes
(SpjfJG)
No
Disconnect
SC20 and SS23
<After Power SW ON,
Power comes up ?
Yes
(SC or SS NG)
JT
Disconnect D33 and D34.
.Disconnect
SC20
(or D20).(*3)
>
_
After Power SW ON,
Power comes up ?
Yes (C or Panel NG)|
^
Power SW OFF.
disconnect
P25 (or D25)..
P25’s 7 or
9
pin Short
with
GND
?
Yves
[SD Board]
No
SU Board
P Board
Disconnect SC20 (or D20).
No
Connect D34. (Disconnect D33)
(Cl or
After
Power SW ON,
Panel
Power comes up ?
Ye^C2 or Panel NG)
Power SW OFF.
No
i*<:
Disconnect all flexible cables
<CB1~CB3 from Cl board.
>-~*]Panel
20pin of IC(*4) in Cl Short
with GND ?
Power SW OFF.
No
Disconnect P25 (or D25).-^
D25’s 7 or
9
pin Short
with
GND
?
Tys
s
D Board P Board
Yes
No
Power SW OFF.
Disconnect all flexible cables
1
<CB4~CB7 from C2 board.
^—I
Panel I
20pin of IC(*4) in C2 Short
with GND ?
Cl Board
Yes
C2 Board
(*1)
VSUS about 180V (Accurate voltage is described in Panel Label on the chassis)
<
Connect
SC20.
Disconnect SS23.
After Power SW ON,
Power comes up ?
Yes
(*2)
Be careful that disconnected SU or SD board doesn’t touch SC board.
N°i
,
>~^
|SC
Board]
SS
Board
(*3)
The reason of disconnect SC20 is to prevent 6 times SOS
caused by
disconnect D33 and D34.
(*4)Check one of the following 1C. <TH-42PD50U>
1C in Cl board : IC7101 or IC7104 or IC7105 or IC7106
1C
in
C2
board :
IC7201
or
IC7202
or
IC7203
or
IC7204
10
4
Power Supply and Protection
Circuit
4
Check Point Location