Philips FM242, Руководство по обслуживанию

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Circuit Descriptions and List of Abbreviations EN 81 FM242 AA 9.
• The RC signal (RC_IN) is routed to the OTC, the VGA1
connector, and the RC-out cinch connector.
• The signals to (+9V_STBY) and from (+9V_STBY_SW) the
'on'/'off' switch are routed to the PSU board.
9.7 Plasma Display Panel (PDP)
9.7.1 General
The PDP, which is used in the FM242, is a product of SDI
(Samsung Display Industry) . When defect, a new panel must
be ordered, and after receipt, the defective panel must be send
for repair in the packing (flight case) of the new ordered panel.
9.7.2 Operation
Principle
Plasma displays work by applying a voltage between two
transparent display electrodes on the front glass plate of the
display. The electrodes are separated by an MgO dielectric
layer and surrounded by a mixture of neon and xenon gases.
When the voltage reaches the 'firing level', a plasma discharge
occurs on the surface of the dielectric, resulting in the emission
of ultra violet light.
This UV light then excites the phosphor material at the back of
the cell and emits visible light. Each cell or sub-pixel has red,
blue or green phosphor material and three sub-pixels combine
to make up a pixel. The intensity of each colour is controlled by
varying the number and width of voltage pulses applied to the
sub-pixel during a picture frame. This is implemented by
dividing each picture frame into sub-frames.(for 50 Hz-mode
there are 12 sub frames, for the 60 Hz-mode there are 10 sub
frames). During a sub-frame, all cells are first addressed -
those to be lit are pre-charged to a specific address voltage -
then during the display time the display voltage is applied to the
entire screen lighting those that were addressed.
Each sub-frame has a weighting-factor. (Time-entity depends
on size and number of pixels on the screen). This is a purely
digital PWM control mechanism, which is a key advantage as it
eliminates any unnecessary digital to analogue conversions.
9.8 Abbreviation list
ADC Analogue to Digital Converter
AM Amplitude Modulation
AP Asia Pacific
AV External Audio Video
B/G Monochrome TV system. Sound
carrier distance is 5.5 MHz
BGA Ball Grid Array
BTSC Broadcast Television Standard
Committee. Multiplex FM stereo sound
system, originating from the USA and
used e.g. in LATAM and AP-NTSC
countries
ComPair Computer aided rePair
CVBS Composite Video Blanking and
Synchronisation
DAC Digital to Analogue Converter
DDC Display Data Channel (a protocol
based on I2C)
D/K Monochrome TV system. Sound
carrier distance is 6.5 MHz
DFU Direction For Use: description for the
end user
DNR Dynamic Noise Reduction
DRAM Dynamic RAM
DSP Digital Signal Processing
DTS Digital Theatre Sound
DVD Digital Versatile Disc
DVI-d Digital Visual Interface, d = digital only
EEPROM Electrically Erasable and
Programmable Read Only Memory
EMI Electro Magnetic Interference
EPLD Erasable Programmable Logic Device
EU Europe
EXT External (source), entering the set via
SCART or Cinch
FLASH Flash memory
FM Frequency Modulation
FSP FTV System Protocol
FTV Flat TeleVision
HP Headphone
I Monochrome TV system. Sound
carrier distance is 6.0 MHz
I2C Integrated IC bus
I2S Integrated IC Sound bus
ICONN Institutional CONNector
IF Intermediate Frequency
Interlaced Scan mode where two fields are used
to form one frame. Each field contains
half the number of the total amount of
lines. The fields are written in 'pairs',
causing line flicker.
IR Infra Red
IRQ Interrupt Request
LATAM Latin America
LED Light Emitting Diode
L/L' Monochrome TV system. Sound
carrier distance is 6.5 MHz. L' is Band
I, L is all bands except for Band I
LS Loudspeaker
LVDS Low Voltage Differential Signalling
M/N Monochrome TV system. Sound
carrier distance is 4.5 MHz
MOSFET Metal Oxide Silicon Field Effect
Transistor, switching device
MPEG Motion Pictures Experts Group
NC Not Connected
NICAM Near Instantaneous Compounded
Audio Multiplexing. This is a digital
sound system, mainly used in Europe.
NTC Negative Temperature Coefficient,
non-linear resistor