Philips 32PFL7403D/10, Руководство по обслуживанию

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Circuit Descriptions, Abbreviation List, and IC Data Sheets EN 134 Q528.2E LB 9.
9.2 Main Supply
9.2.1 32" Sets
The 32" sets in this chassis can come with two different buy-in
(Delta) supply units:
•
PLCD170PS09B.
• DPS-182CP A.
When defective, a new panel must be ordered and the
defective panel must be sent for repair, unless the main fuse of
the panel is broken. Always replace a defective fuse with one
with the correct specifications! This part is available in the
regular market.
Refer to the Spare Parts list for the order number of the supply
unit.
DPS-182CP A
The supply unit delivers the following voltages to the chassis:
•
24 V
inv
(connector CN2 and CN3, LCD panel,
14 and 12 pins)
• 24 V
A
(connector CN4, Ambilight, 6 pins).
• 12 V
B
(connector CN5, Bolt-on, 4 pins)
• +12 V
B
(connector CN5a, Bolt-on provisional, 4 pins)
• 3.3 V
SB
, 12 V, +12 V
audio
and -12 V
audio
(connector CN6,
SSB, 11 pins)
• +12 V (connector CN7, SSB, 8 pins).
DC output protections - Short Circuit Protection
The 3.3 V standby power circuit has short circuit protection with
an auto restart function and an over voltage protection which
operates within a range of 120 to 140% of the nominal value.
In case a short-circuit situation occurs at the 12 V, 12 V
B
or
24 V
A
output the over voltage protection operates within a
range of 120 to 140% of the nominal value.
In case a short-circuit situation occurs at one of the + 12 V
A
or
- 12 V
A
outputs, the over voltage protection intervenes at a
maximum value of 19 V.
In case a short-circuit situation occurs at the 24 V
INV
output, the
supply unit will auto-recover when the fault condition is
removed. It operates within a range of 120 to 140% of the
nominal value.
9.2.2 37" Sets
The 37" sets in this chassis come with a buy-in Supply unit and
is a black-box for Service. When defective, a new panel must
be ordered and the defective panel must be sent for repair,
unless the main fuse of the panel is broken. Always replace a
defective fuse with one with the correct specifications! This part
is available in the regular market.
Refer to the Spare Parts list for the order number of the Supply
unit.
9.2.3 42" Sets
The 42" sets in this chassis come with a buy-in Delta Supply
unit and is a black-box for Service. When defective, a new
panel must be ordered and the defective panel must be sent for
repair, unless the main fuse of the panel is broken. Always
replace a defective fuse with one with the correct
specifications! This part is available in the regular market.
Refer to the Spare Parts list for the order number of the Supply
unit.
The Supply unit delivers the following voltages to the chassis:
•
High voltage to drive the backlight units (no inverters
needed)
• 3.3 V
SB
(connector CN6)
• 12 V (connector CN7)
• +12 V
A
(connector CN6)
• - 12 V
A
(connector CN6)
• 24 V
A
(connector CN4).
DC output protections
Over Voltage Protection
In case of an over-voltage situation, the Supply unit will shut
down. To restart: disconnect from AC, except in the event the
over-voltage situation occurred at the 3.3 V
SB
output (auto-
recovery).
Short Circuit Protection
In case a short-circuit situation occurs at the 12 V, 12 V
B
or 24
V
A
output, the Supply unit will shut down. To restart: disconnect
from AC.
In case a short-circuit situation occurs at one of the + 12 V
A
or
- 12 V
A
outputs, the fuse will break.
In case a short-circuit situation occurs at the 3.3 V
SB
output, the
Supply unit will auto-recover when the fault condition is
removed.
AC output protections
Both Short-Lamp and Open-Lamp protections have been
foreseen. To restart: disconnect from AC.
9.2.4 47" Sets
The 47" sets in this chassis come with a buy-in Supply unit and
is a black-box for Service. When defective, a new panel must
be ordered and the defective panel must be sent for repair,
unless the main fuse of the panel is broken. Always replace a
defective fuse with one with the correct specifications! This part
is available in the regular market.
Refer to the Spare Parts list for the order number of the Supply
unit.
9.3 Front-End
Refer to figure “9-1 Architecture of TV522 platform” earlier in
this chapter for details. Refer also to block diagrams B03A,
B03B and B03C.
9.3.1 Device specifications
Tuner (TD1716)
The tuner has the following specifications:
•
Hybrid tuner with symmetrical IF output.
• Down conversion from RF to IF frequency (picture carrier
39.875 MHz at analogue reception, centre frequency
36.166 MHz at digital reception).
• AGC control signal is coming from master IF device
(TDA9898).
• Only 5 V external supply needed (internal DC-DC
conversion to 3.3 V).
• 4 MHz output is used by channel decoder (TDA10048) and
master IF device (TDA9898).
The application in this chassis is as follows:
•
I
2
C address C0.
• Broadband AGC, no IF section.
• I
2
C communication buffered via MUX.
• Gain to obtain optimised Master IF input level; AGC control
is completely inside the tuner.
• Output level ca. 110 dB
μ
V (for strong input signal).
Repair tip: after replacement of the tuner, the option code
should be checked, even when the set appears to function
correctly! Refer also to chapter 5 “Service Modes, Error Codes,
and Fault Finding”.
Master IF (TDA9898)
• Down conversion from IF to low-IF frequency.
• Down conversion from IF to SIF.
• CVBS output.