Hitachi 22LD4500UK, Service Manual

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1. INTRODUCTION
22” TFT-LCD TV is a Progressive TV control system based on the
µ
-controller SDA555X, with built-in de-
interlacer and scaler .
TFT TV is a progressive scan flicker free colour television with PC input, driving an WXGA (1280*720)
panel with 16:9 aspect ratio. The chassis is capable of operation in PAL, SECAM, NTSC (playback) colour
standards and multiple transmission standards as B/G, D/K, I/I’, and L/L´. Sound system output is
supplying 2x3W (10%THD) for left and right outputs of 16O speakers. The chassis is equipped with two full
SCART’s, one front-AV, one SVHS, one D-Sub 15 (PC) input, one PC stereo audio input and one line out
(left and right) and one HP outputs.
2. TUNER
As the thickness of the TV set has a limit, a horizontal mounted tuner is used in the product, which is
suitable for CCIR systems B/G, H, L, L´, I/I´, and D/K. The tuning is available through the digitally
controlled I
2
C bus (PLL). Below you will find info on the Tuner in use.
General description of UV1316:
The UV1316 tuner belongs to the UV 1300 family of tuners, which are designed to meet a wide range of
applications. It is a combined VHF, UHF tuner suitable for CCIR systems B/G, H, L, L’, I and I’. The low IF
output impedance has been designed for direct drive of a wide variety of SAW filters with sufficient
suppression of triple transient.
Features of UV1316:
1. Member of the UV1300 family small sized UHF/VHF tuners
2. Systems CCIR: B/G, H, L, L’, I and I’; OIRT: D/K
3. Digitally controlled (PLL) tuning via I
2
C-bus
4. Off-air channels, S-cable channels and Hyper band
5. Compact size
6. Complies to “CENELEC EN55020” and “EN55013”
Pinning:
1. Gain control voltage (AGC) : 4.0V, Max: 4.5V
2. Tuning voltage
3. I²C-bus address select : Max: 5.5V
4. I²C-bus serial clock : Min:-0.3V, Max: 5.5V
5. I²C-bus serial data : Min:-0.3V, Max: 5.5V
6. Not connected
7. PLL supply voltage : 5.0V, Min: 4.75V, Max: 5.5V
8. ADC input
9. Tuner supply voltage : 33V, Min: 30V, Max: 35V
10. Symmetrical IF output 1
11. Symmetrical IF output 2
3. IF PART (TDA988X)
The TDA9885 is an alignment-free single standard (without positive modulation) vision and sound IF signal
PLL.
The TDA9886 is an alignment-free multistandard (PAL, SECAM and NTSC) vision and sound IF signal
PLL demodulator for positive and negative modulation including sound AM and FM processing.
Both devices can be used for TV, VTR, PC and set-top box applications.
4. MULTI STANDARD SOUND PROCESSOR
The MSP34x0G family of single-chip Multistandard Sound Processors covers the sound processing of all
analog TV-Standards worldwide, as well as the NICAM digital sound standards. The full TV sound
processing, starting with analog sound IF signal-in, down to processed analog AF-out, is performed on a
single chip.
These TV sound processing ICs include versions for processing the multichannel television sound (MTS)
signal conforming to the standard recommended by the Broadcast Television Systems Committee (BTSC).
The DBX noise reduction, or alternatively, Micronas Noise Reduction (MNR) is performed alignment free.
Other processed standards are the Japanese FM-FM multiplex standard (EIA-J) and the FM Stereo Radio
standard.
Current ICs have to perform adjustment procedures in order to achieve good stereo separation for BTSC
and EIA-J. The MSP 34x1G has optimum stereo performance without any adjustments.