Circuit Descriptions
7.
7.3
Power
S
upply
All power supplies used in this chassis are a “black box” for
Service. When defective, a new board must be ordered and the
defective one must be returned, unless the main fuse of the
board is broken. Always replace a defective fuse with one with
the correct specifications! This part is available in the regular
market.
Consult the Service Spare Part portal for the order codes of
these boards.
Below some background info on the PSUs is given, to ease the
troubleshooting process in case of power supply problems
7.3.1
Diversity
The only type of power supply used in this platform is the
Integrated Power Board (IPB) - incl. LCD backlight inverters.
Below find an overview of the different PSUs that are used:
Table 7-1
S
upply diversity
It should be noted that for different display manufacturers,
different PSUs can be used. When ordering a new PSU,
always check which LCD panel is used in the set, and order the
correct PSU!
7.3.2
IPL32L P
S
U
Block Diagram
Figure 7-2 Block diagram IPL32L P
S
U
Key Components
The key component ICs are:
•
Stand-by power supply IC: FSQ510 (Fairchild).
•
PFC control IC: L6563 (ST).
•
24V PWM control IC: FA5571N (FUJI).
•
Inverter high voltage control IC: OZ9976 (O2).
Control Signals
Table 7-2 Control signals
Output Characteristics
Table 7-3 Output characteristics
Fault Finding
Figure 7-3 Fault finding diagram IPL32L P
S
U
S
upplier
P
S
U
Model
Input Voltage Range
TCL
IPL32L
32" LG display
100 - 240 Vac
IPL42L
42" LG display
Control signal
Comments
Output
PS-ON
3.3V >= ON >= 2.0V
AC power output ON
0.7V >= OFF >= 0V
AC power output OFF
BL_ON
5.0V >= ON >= 2.0V
The inverter is working
1.0V >= OFF >= 0V
The inverter is switched OFF
DIMP
High level: 2V ~ 5.0V
HD: OPC dimming, 140Hz
Low level: 0V ~ 0.7V
FHD: PWM, 103.4Hz
Output Voltage Tolerance Min. current Max. current
Load regulation
+3V3(STB)
+/- 3%
5 mA
200 mA
+/- 5%
24V
+/- 5%
0.2 A
2.0 A
+/- 5%
1
8
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3
19.ep
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V no rm
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Y
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N
N
N
C B 1 v o lt
a
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no rm
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no rm
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N
24V no rm
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F
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m o v em ent
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a
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N
F
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m o v em ent
Check
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t
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Y
F
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W hether the
b
rid g e rec tif ier
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it
P F C IC , f eed
b a
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drive f
a
il
u
re, etc .
Y
P F C p o w er
s u
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p
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rt (Q W 11) f
au
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Y
P W M IC , f eed
b a
c k,
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a
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s
f o rm er f
a
il
u
re
s
, etc .
N
Y
A ttentio n :
a
l
s
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the P F C
a
nd P W M c o ntro l,
s
ho rt-c irc
u
it in o rd er to
rep l
a
c e the F
us
e
a
nd
B rid g e.
Y
H V p
a
rt f
a
il
u
re
(IC p ro tec tio n
circ
u
it).
s u
c h
as
w hether the MO
S
