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7.3
Power Supply
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 Supply diversity
Supplier
PSU
IPL32L
IPL42A
TCL
IPL42L
IPL47L
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!
All manuals and user guides at all-guides.com
Model
Input Voltage Range
32" LG display
42" AUO display
100 - 240 Vac
42" LG display
47" LG display
Circuit Descriptions
7.3.2
IPL32L PSU
Block Diagram
A C IN
B rid g e re ctifie r
E M C
F ilte r circu it
F ilte r circu it
1 2 V R e la y K 1
P F C C ircu it
B rid g e re ctifie r
F ilte r circu it
H V tra n sfo rm e r
H ig h Vo lta g e
A C o u tp u t
Figure 7-2 Block diagram IPL32L PSU
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
Control signal
Comments
PS-ON
3.3V >= ON >= 2.0V
0.7V >= OFF >= 0V
BL_ON
5.0V >= ON >= 2.0V
1.0V >= OFF >= 0V
DIMP
High level: 2V ~ 5.0V
Low level: 0V ~ 0.7V
Output Characteristics
Table 7-3 Output characteristics
Output Voltage Tolerance Min. current Max. current
+3V3(STB)
+/- 3%
24V
+/- 5%
Fault Finding
S w itc h "o n"
3.3V no rm al?
Y
P S _O N no rm al?
Y
R elay is c lo s ed ?
Y
P F C v o ltag e
no rm al?
Y
B L_O N and
D IM P normal?
Y
H V p art f ailure
(IC p ro tec tio n
circuit).
Figure 7-3 Fault finding diagram IPL32L PSU
TCM3.1A LA
7.
S ta n d b y
circu it
3 .3 V
IC 3 / T2
O p to
co u p le r
V CC
P W M
IC 1
C ircu it
2 4 V
395V
L 1
IC 2
T1
12V o p erating v o ltag e
BL-ON
IN V E R TE R
T4
C o n tro l a n d
d rive circu it
F e e d b a ck circu it
P ro te ctio n circu it
Output
AC power output ON
AC power output OFF
The inverter is working
The inverter is switched OFF
HD: OPC dimming, 140Hz
FHD: PWM, 103.4Hz
5 mA
200 mA
0.2 A
2.0 A
N
N
C B 1 v o ltag e
no rm al?
Y
Check S tand b y IC , f eed b ac k,
trans f o rm er f ailures , etc .
N
A ttentio n : als o c hec k
F ault
m o v em ent
the P F C and P W M c o ntro l,
s uc h as w hether the MOS
s ho rt-c irc uit in o rd er to
rep lac e the F us e and
N
R elay p o w er s up p ly
p art (Q B 1) f ault
P W M IC , f eed b ac k,
trans f o rm er f ailures, etc .
N
N
P F C _V C C
no rm al?
Y
P F C IC , f eed b ac k,
P F C p o w er s up p ly
drive f ailure, etc .
part (Q W 11) fault
N
F ault
m o v em ent
EN 23
M C U
PS - ON
S tartup
S ig nal
C ircu it
PDIM
18520_211_090319.eps
090319
Load regulation
+/- 5%
+/- 5%
F us e is o p en
W hether the
b rid g e rec tif ier
c irc uit
Y
B rid g e.
N
24V no rm al?
Y
18520_212_090319.eps
090319
2010-Jun-25
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