Philips FTV1.9 Service Manual

PSSG

PHILIPS SERVICE SOLUTIONS GROUP

FTV1.9 DISPLAY PANEL

AND E-BOX

TRAINING MANUAL

E BOX

PHILIPS

TECH

VIDEOTAPE S

MANUALS

PHILIPS TECHNICAL TRAINING
ONE PHILIPS DRIVE
PO BOX 14810
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FAX: [phone]

TRAINING

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PLASMA DISPLAY

TABLE OF CONTENTS

PLASMA DISPLAY INTRODUCTION 1
POWER SUPPLY 2
POWER ON CIRCUITS 5
SHUTDOWN CIRCUITS 12
PLASMA PANEL VIDEO FLOW 12
PLASMA PANEL AUDIO 16
PLASMA PANEL BOARD LEVEL TROUBLESHOOTING 19
PLASMA PANEL BOARD LOCATION 29
PLASMA PANEL CUSTOMER SERVICE MODE 30
PLASMA PANEL DISASSEMBLY 31
E-BOX INTRODUCTION 35
E-BOX REAR VIEW 36
E-BOX BOARD LOCATION 37
E-BOX VIDEO SIGNAL FLOW 39
E-BOX WIRING INTERCONNECT 36
E-BOX SERVICE ALIGNMENT MODE 47
E-BOX CUSTOMER SERVICE MODE 48
E-BOX SYSTEM CONTROL 49

ADDRESS ELECTRODES

BARRIER RIBS

INTRODUCTION

The FTV1.9 Chassis has a 42 inch diagonal display which uses Plasma Display technology. The
Receiver or E-Box contains the Tuning System and AV inputs. The E-Box and Display are designed
to work together. Both can be operated alone.

Both the Display and E-Box have IR inputs to allow operation of the units by Remote. The Display
can only be operated by a Remote Control. When the E-Box is connected to the Display, the IR
Receiver in the E-Box is disabled unless the unit is placed in the Service Mode. When the E-Box is
connected to the Display, the AV inputs on the Display are disabled. The Display cannot be placed
in the Service Mode while the E-Box is connected.

The Display has a VGA in, a VGA out which is a loop though from the VGA in, two composite
inputs, and one Y Cr Cb component inputs. The AV inputs, which are the two composite inputs and
the Component input, become active when the Display is operated alone.

PLASMA DISPLAY

The Display has a resolution of 852 x 480 pixels. The Display consists of a series vertical repeating
Red, Green, and Blue phosphor strips. These strips are separated by Barrier Ribs that are activated
by Address Electrodes.

Page 1

DISPLAY ELECTRODES

Display Electrodes are
placed over the channels
in the Horizontal direction.

The Display is then
covered by a glass plate.

A voltage is applied to the
Red, Green, and Blue
Address Electrodes
corresponding to the
desired brightness and
color of the displayed
pixel. A Voltage is then
applied to the Display
Electrode for the line that
the pixel is to be dis­played.

NOTES:

Page 2

POWER SUPPLY

Power Supply Block (Figure 1)

AC power for the Display is applied to the Line Conditioner panel. The Line Conditioner panel has
the 5 volt Standby supply, On/Off Relays, and a Boost Regulator. The 5 volt Standby supply is
present whenever power is applied to the unit. The Standby voltage is routed through the VS-VA
panel, AV Control panel, to the Switch panel. When the Power Switch on the Switch panel is turned
On, the 5 volts Standby supply is applied to the Microprocessor on the AV Control panel, Switching
circuits on the VS-VA supply panel, and the Control circuits on the Line Conditioner panel.

When the set is turned On, the Standby line from the Microprocessor goes Low. The Error Detect
circuit on the VS-VA Supply panel switches the Standby line to the Line Conditioner panel High.
The Control circuit on the Line Conditioner panel switches the Relays On, applying power to the
Boost Regulator circuit. This circuit outputs 380 volts dc to the VS and VA supplies on the VS-VA
Supply panel. The VS supply output 180 volts to the Sequencer panel and then to the Plasma
Display. The VA supply outputs a 65 volt supply for the Plasma Display, a 17 volt supply for the Fan
circuits and the secondary regulators. It also outputs a plus and minus 19 volt supplies to the Audio
Amplifier circuits. The 17 volt supply feeds a 5.2 and 8.6 volt regulators.

NOTES:

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Page 4

FIGURE 1 - POWER SUPPLY BLOCK

FIGURE 2 - STANDBY POWER SUPPLY

5500

Page 5

Standby Power Supply (Figure 2)

The Standby Power Supply produces a +5 Volt Standby and a +12 volt Standby supplies. This is a
Pulse Width type switching power supply. Power is applied to this circuit when power is applied to
the unit. This Supply is located on the Pre-Conditioner panel. When Power is first applied to the
circuit, the internal switch in 7500 applies a charging voltage to 2504, which is connected to Pin 4.
When 2504 charges to 5.7 volts, the internal switch switches to internal. Capacitor 2504 is now
supplying power to the PWM. The internal switch then drives the internal FET to drive transformer

5500. 7500 continues to drive the transformer until 2504 discharges to 4.7 volts. Capacitor 2504
is again charged and the cycle is then repeated. When the secondary 5 volt supply reaches the
correct voltage, 7502 is turned on, driving the opto-isolator 7501. Voltage from the Hot secondary is
rectified by 6503 and applied to 7501. Voltage from 7501 then keeps 2504 charged to 5.7 volts. An
internal Zener Diode, inside 7500, keeps the voltage at 5.7 volts. Regulation is accomplished via
the shut regulator 7502, opto-isolator 7501, and the internal current sensing resistor in 7500. If the
5 volt supply increases, the shunt regulator drives 7501 harder causing an increased voltage drop
across the internal sensing resistor Rs inside 7500. The PWM will then reduce the On time in the
internal FET, reducing the output voltage.

POWER ON CIRCUIT

When the mechanical On/Off switch is turned On, the 5 volts Standby voltage is switched to the
+5VSTBYSW-REL and +5VSTBYSW lines. (Figure 3) When the Power is turned On via the Remote
Control, Pin 1 of the Microprocessor, 7001, goes Low. This switches 7370 Off. The Supply On line
then goes High via the +5VSTBYSW line. If one of the Shutdown circuits is activated, 7371 is
turned On which turns 7370 On, turning the set Off.

The +5VSTBYSW and Supply On lines are fed to the Line Conditioner panel. (Figure 4) There is a
two stage turn On to supply power to the Line Conditioner circuit. When the Supply On line goes
High, 7681 turns On, switching relay 5680 On. Capacitor 2683 provides a short delay for the turn
On of 7684 and 7690 which turns relay 5690 On. The Line Conditioner circuit provides 380 volts dc
to the VS-VA Power Supplies.

The VS and VA supplies are Frequency controlled supplies. (Figure 5) The output transformer,
5002, and related components form a Resonant circuit. As the Frequency of the supply approaches
the resonant frequency of the output circuit, the output voltage increases. When the unit is turned
On, 380 volts dc form the Line Conditioner circuit is applied to the switching FET, 7005. A Startup
voltage is applied to Pin 15 of 7001. The Variable Frequency Oscillator drives transformer 5001
which drives the output switches, 7005 and 7006. A Feedback Error voltage from the secondary
controls the Variable Frequency Oscillator to control the Output voltage. The Fault Detect latch is
activated if a problem is detected on the secondary. The VA Supply is identical to the VS supply.

The VS supply outputs a 180 volts supply for the Plasma Panel. (Figure 6) Secondary voltage on
Pins 13 and 12 of 5002 is rectified by 6020 to produce the 180 volt supply. Feedback for the Error
Amplifier to regulate the supply is accomplished by sampling the 180 volt supply and by a feedback
Vrs signal from the Plasma Panel. The 180 volt supply is sampled by 3024, 3025, and 3026. The
sampled voltage feeds shunt regulator 7010 which drives the opto-isolator 7002. Feedback voltage
from the Plasma Display feeds shunt regulator 7011, which also drives 7010. The Feedback circuit
is powered by voltage from Pin 14 of 5002.

Page 6

FIGURE 3 - POWER ON CIRCUIT

FIGURE 4 - LINE CONDITIONER POWER ON

Page 7

FIGURE 5 - VS SUPPLY BLOCK

Page 8

FIGURE 6 - VS SUPPLY OUTPUT

FIGURE 7 - VA SUPPLY OUTPUT

Voltage from Pins 13 and 12 of 5102 are rectified by Bridge 6120 to produce the 65 volt VA supply.
(Figure 7) Voltage from Pins 16 and 14 are rectified by Diodes 6121 and 6122 to produce the 17
volt supply. Voltage from Pin 11 is rectified by 6202 to produce the minus 19 volt supply. Diode
6201 rectifies voltage from Pin 11 to produce the plus 19 volt supply. These voltages are used to
power the Audio Amplifier. When checking voltages in the Audio circuit, use the Audio Ground. If
either of the plus or minus 19 volt supplies are lost, the Audio Protection circuits will shut the set
down. These circuits are discussed later in this manual.

FIGURE 6 - VS SUPPLY REGULATOR AND SHUTDOWN

Page 9

FIGURE 8 - VA REGULATION FEEDBACK

The 65 volt supply is used as a reference voltage for the VA supply. (Figure 8) The VA supply is
sampled by resistors 3124, 3125, and 3126 to produce a reference voltage to drive Shunt Regulator

7110. Variable Resistor 3126 is used to set the VA supply to the correct voltage. Additional control
for the supply from the Plasma Display is fed to Shunt Regulator 7111 via the Vra voltage.
Regulator 7111 drives 7110. If the Vra voltage is missing, the set will go into shutdown. The 17 volt
supply powers the Feedback circuit. Regulator 7110 drives the opto-isolator 7102 which provides a
correction voltage to the Error Amp in 7101.

Page 10

FIGURE 9 - 5.1 AND 8.6 VOLT SUPPLY BLOCK

The 17 volt supply feeds the Switching Regulator 7201 which produces the 5.1 volt source. (Figure

9) The output of the Regulator also feeds the 8.6 volt regulator 7203. If the 5.1 volt source reaches

7.4 volts, Zener diode 6205 will conduct, switching SCR 7202 On. This will cause fuse 1103 to
open. The failure of these supplies will cause the set to shut down.

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FIGURE 10 - SEQUENCER PANEL

The VS and VA supplies are fed to the Sequencer panel. The Vrr signal from the Plasma Display is
monitored by the Sequencer Panel. (Figure 10) If there is a problem on the Plasma Display, the
Vrr line will go Low. Transistor 7701 will turn Off. This will cause transistors 7702 and 7703 to turn
On. The VSTART line will go Low which will shut the VA Supply down. This will cause the set to
shut down and generate an error code. Transistor 7704 will also turn Off, shutting Off the VA supply
to the Plasma Display.

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FIGURE 11 - OVERVOLTAGE PROTECTION

The VS and VA supplies are monitored for overvoltage. If the 65 volt VA supply goes High, the input
to Shunt Regulator 7112 will go to 2.5 volts, causing 7112 to conduct. This turn on 7113 which will
turn On SCR 7114 which will cause the Aa line go Low. In addition, Transistor 7341 will turn On,
switching the Protection Status line High. If the VA supply reaches 67.75 volts, the set will go into
shutdown. The VS supply is sampled by resistors 3033, 3058, and 3034. If the VS supply reaches
198 volts, the input to Shut Regulator 7012 will go to 2.5 volts, turning 7012 On. This will turn On
7017 and SCR 7013. The Aa line will go Low, turning the set Off.

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FIGURE 12 - FAN PROTECTION CIRCUIT

To prevent damage to the Plasma Display, the Fans are monitored to ensure that they are all
working. (Figure 12) If any of the Fans should fail, the set will go into shutdown and error code will
be generated by the Microprocessor. When the Fans are operating, Transistors 7316, 7317, 7318,
7319, and 7320 are turned On. This keeps the FAN-PROT line Low. If any of the Fans fail, the
Transistor monitoring that fan will turn Off. When the collector reaches 9.4 volts, the FAN-PROT line
will go to 0.6 volts activating the Shutdown circuits.

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FIGURE 13 - SHUTDOWN CIRCUITS

Page 15

SHUTDOWN

As shown in Figure 3, the Shutdown circuit turns the set Off in the event of a failure which could
damage the set. (Figure 13) If one of the Fans should fail, the Fan Fail Detect circuit will go High
turning SCR 7315 On. This will turn 7321 On, turning 7339 On, turning 7338 On, turning SCR 7333
On, which will turn 7371 On. This will turn the set Off. If a problem develops in the Audio circuit,
the DC-PROT line will go High, causing the same switching action, which will cause the set to shut
down. A thermistor on the Line Conditioner panel monitors for an excessive temperature problem.
If this circuit senses a problem, the opto-isolator 7331 will conduct, turning SCR 7332 On. This will
turn 7337 On, causing the set to shut down. If the Aa line, shown in Figure 6, goes Low, 7341 will
turn On, which will turn 7339 On, causing the set to shut down. If the PROTECTION STATUS line
goes High, the set will shut down.

The VS and VA supplies are monitored for any negative spikes by 3362, 3363, 3360, and 3361. If
any negative spikes occur, 7335 will turn Off, 7336 will turn On. The output of 7301-B will then go
High turning SCR 7302 On, causing the set to shut down. The Vrr voltage from the Plasma display
is also monitored by 7301-B. If this voltage drops, 7301-B goes High, shutting the set Off.

Connector FD176, Pin2 is connected to the Sequencer Panel (This panel may also be labeled
Discharge Panel). On the Sequencer panel, this line is labeled V-Start. If this line goes Low,
opto-isolator 7003 turns On. This causes the Fault Detect Latch line to the VS supply to go High,
shutting the supply Off.

PLASMA PANEL VIDEO SIGNAL FLOW

When the Display panel is used without the E-Box, Composite and Component inputs to the panel
are via the INPUT panel. (Figure 14) If the input is a NTSC Component input signal, the Y Cr Cb
signals are buffered by 7020, 7014, and 7025. These signals are fed to the YUV to RGB matrix.
This signal is then fed to 7013, Signal Processor. There are two Composite inputs to the panel.
The Comb Filter IC 7080 selects the desired Composite input. YC from the Comb Filter is fed to
switch IC 7095 which selects between the Comb Filter and the SVHS input. The selected YC signal
is then fed to the Signal Processor. This signal is then converted to a YUV and then to an RGB
signal inside the Signal Processor. The Signal Processor then selects RGB from the Component
input or from 7095. RGB is then output to the Audio Video Control panel. The Signal Processor
also separates Horizontal and Vertical Sync which is also fed to the Audio Video Control panel.

The E-Box provides signal and communication to the Display via the VGA in connector, AVC32.
(Figure 15) The RGB signal is also routed to the VGA-OUT connector, allowing more than one
Plasma Panels to be connected. For troubleshooting purposes, a computer monitor can also be
connected to this port.

The RGB signal is fed to 7360 which switches between the VGA-IN and RGB from the YC panel.
The RGB signal is then fed to 7300 which provides clamping, brightness, and contrast control. This
signal is then buffered and sent to the PDP Limesco panel. Black Level Feedback signals, FB-R,
FB-G, and FB-B are provided by the Gamma Amplifier on the PDP Limesco panel. This is to insure
proper dc coupling between the two panels.

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