Used ICs: STR F6454R(SMPS
control), MSP34J7G(NICAM processor), TDA9365 / TDA9384 / TDA9386(MICOM Chroma
Jungle), TDA9859(Ausio output IC), ba7604N, TDA8356(Vertical Scan output IC)
In V3AR ,failure of Main devices can detect by the blinking indication of LED at front panel.( Example : LED blinking time is 2 in cycle I002 is out of order. )
If an IIC error occurred, the LED, D001 blinks at 1Hz, 50% duty cycle.
The blinking times are as below
Click on the pictures to magnify
Selection and CPU circuitry
IC type, TDA9381/86/65 performs functions like IIC controls, channel selection, on-screen display, search tuning, systems selection amongst others. The pin's functions of TDA9381/86/65 are presented in the table shown below.
IC type, TDA9381/86/65 performs functions like IIC controls, channel selection, on-screen display, search tuning, systems selection amongst others. The pin's functions of TDA9381/86/65 are presented in the table shown below.
The Tuner (U001)used on V3AR
chassis is powered up by the 5V supply. It is IIC bus controlled and covers
VHF, UHF, CATV Band (Mid, super, and hyper).
The IF output from Tuner ( pin 11 of U001) is applied to the amplifier Q201.
For multi-system model with M-NTSC, switchable saw filter is used. Q001 at pin 2 of X003 servers to select the IF signal between M/N mode to other modes ( e.g. B/G, D/K ) before demodulation is carried out at I001.
i.e. at M mode: Base of Q001 High
I001 (TDA9381/9386/9365) besides begin the microcontroller, incorporates video / chroma / deflections / teletext features and video/audio switching. It performs auto color identification of PAL/SECAM/NTSC, sync separation , AFC, HV oscillator and output RGB signals.
The IF output from Tuner ( pin 11 of U001) is applied to the amplifier Q201.
For multi-system model with M-NTSC, switchable saw filter is used. Q001 at pin 2 of X003 servers to select the IF signal between M/N mode to other modes ( e.g. B/G, D/K ) before demodulation is carried out at I001.
i.e. at M mode: Base of Q001 High
I001 (TDA9381/9386/9365) besides begin the microcontroller, incorporates video / chroma / deflections / teletext features and video/audio switching. It performs auto color identification of PAL/SECAM/NTSC, sync separation , AFC, HV oscillator and output RGB signals.
IF signal is sent to I001 pin 23
and 24 for demodulation. For MONAURAL and AV STEREO mode, the demodulated signals
are sent for video and audio selection. For NICAM/A2 mode, the demodulated
signals are sent for video processing only.
The composite video signals after demodulation are sent to a series of band pass filters (X004 - X006) through pin 38 of I001.
The composite video signals after demodulation are sent to a series of band pass filters (X004 - X006) through pin 38 of I001.
The selected RF video signal is
sent to pin 40 of I001 and output AV terminal. The external video signal from
input AV 1 and 2 terminal also goes through pin 38 to output AV terminal. This
is done by use of internal switch control.
Audio mode switching
For MONAURAL (without NICAM/A2) sound models, two audio switching is carried out. The RF audio signal after demodulation in I001 is output at pin 28 of I001 to pin 10 of I401. I401 perform audio selection using control signal between the RF audio signal and external audio signal input (pin 8) of I401. The audio output at pin 6 of I401 is sen
to output AV terminal.
The external audio input is also sent to pin 35 of I001 to perform the second audio switching with the RF audio signal in I001. The selected audio signal goes through volume control before output at pin 44 of I001 to L(pin2) and R(pin 5) of I402. Amplification took place and output at L (pin12) and R (pin7) of I402 to the speakers
For NICAM/A2 sound models, the IF signal is input at pin 1 of X002 (saw filter) and output at pin 4 and 5 to pin 28 and pin 29 of I001. After demodulation, the audio signal output at pin 35 to NICAM PWB (pin 2 of EN01) for NICAM processing. The NICAM audio output at pin L (pin 10) and R (pin 11) of EN01 goes to SOUND PWB at pin 9 and 10 of EA01 For AV STEREO sound models, the audio signal is output at pin 44 of I001 and goes to SOUND PWB at pin 9 and 10 of EA01.
Audio input (L and R) from AV 1 And 2 terminal are input to pin 1 - 4 of EA01. Audio switching, volume control, treble and bass are processed at IA01 (TDA9856). The L (pin 7) and R (pin6) output at EA01 goes to output AV terminal The L (pin 12) and R (pin 11) at EA01 goes to I402 for amplification before sending to the speakers.
For MONAURAL (without NICAM/A2) sound models, two audio switching is carried out. The RF audio signal after demodulation in I001 is output at pin 28 of I001 to pin 10 of I401. I401 perform audio selection using control signal between the RF audio signal and external audio signal input (pin 8) of I401. The audio output at pin 6 of I401 is sen
to output AV terminal.
The external audio input is also sent to pin 35 of I001 to perform the second audio switching with the RF audio signal in I001. The selected audio signal goes through volume control before output at pin 44 of I001 to L(pin2) and R(pin 5) of I402. Amplification took place and output at L (pin12) and R (pin7) of I402 to the speakers
For NICAM/A2 sound models, the IF signal is input at pin 1 of X002 (saw filter) and output at pin 4 and 5 to pin 28 and pin 29 of I001. After demodulation, the audio signal output at pin 35 to NICAM PWB (pin 2 of EN01) for NICAM processing. The NICAM audio output at pin L (pin 10) and R (pin 11) of EN01 goes to SOUND PWB at pin 9 and 10 of EA01 For AV STEREO sound models, the audio signal is output at pin 44 of I001 and goes to SOUND PWB at pin 9 and 10 of EA01.
Audio input (L and R) from AV 1 And 2 terminal are input to pin 1 - 4 of EA01. Audio switching, volume control, treble and bass are processed at IA01 (TDA9856). The L (pin 7) and R (pin6) output at EA01 goes to output AV terminal The L (pin 12) and R (pin 11) at EA01 goes to I402 for amplification before sending to the speakers.
POWER SUPPLY CIRCUIT
Commutating voltage from AC output rectified by D901A and produces approximately 300V to pin 3 of I901.
Current flowing through R904, R917, causes I901 pin 4 to initially turn on.
Secondary voltage are then induced winding V1 - V2 in T901, I901 supply voltage is obtained via R906, D906, C909 and applied to pin 4 of I901, thereby maintaining I902 switching operation. Secondary voltage in S1, S3 winding is rectified by D951 to produce +B = 95V which is smoothed by C953. S2, S4 winding produces 16V from D952, and this is smoothed by C956.
Error amplifier Q951 is set to a pre-determined level by resistor network R952 - R956, and reference voltage D957 Should the +B voltage rise, base voltage of transistor Q951 will become more positive, and this difference is amplified by the error amplifier Q951. An output is applied to I901 feedback pin 1 through optocoupler (CTR) I902 and controls ON time of I901 internal circuit . In this way, +B voltage is regulated and maintained at a constant level.
D973 offers protection that it should the voltage level rise excessively
When the standby mode is selected, pin 1 of I001 will go " low " . As a result Q954 and Q955 are turned off, and the supply voltage for the horizontal start of pin 33 of I001 though R980/D980/R071 disappears. Therefore shutting down the deflection drive stages of I001, deflection output stage will then cease for as long as the standby condition exist.
Commutating voltage from AC output rectified by D901A and produces approximately 300V to pin 3 of I901.
Current flowing through R904, R917, causes I901 pin 4 to initially turn on.
Secondary voltage are then induced winding V1 - V2 in T901, I901 supply voltage is obtained via R906, D906, C909 and applied to pin 4 of I901, thereby maintaining I902 switching operation. Secondary voltage in S1, S3 winding is rectified by D951 to produce +B = 95V which is smoothed by C953. S2, S4 winding produces 16V from D952, and this is smoothed by C956.
Error amplifier Q951 is set to a pre-determined level by resistor network R952 - R956, and reference voltage D957 Should the +B voltage rise, base voltage of transistor Q951 will become more positive, and this difference is amplified by the error amplifier Q951. An output is applied to I901 feedback pin 1 through optocoupler (CTR) I902 and controls ON time of I901 internal circuit . In this way, +B voltage is regulated and maintained at a constant level.
D973 offers protection that it should the voltage level rise excessively
When the standby mode is selected, pin 1 of I001 will go " low " . As a result Q954 and Q955 are turned off, and the supply voltage for the horizontal start of pin 33 of I001 though R980/D980/R071 disappears. Therefore shutting down the deflection drive stages of I001, deflection output stage will then cease for as long as the standby condition exist.
Shipping Data of IIC Service Mode. (apply only when the memory IC, I002, change.)
1. Select the adjustment item, 323(Initialization of memory IC, I002) by pressing the Up or Dn cursor button on Remote control handset.
2. Set data of adjustment item, 323 to "01" by pressing the Left or Right cursor button on Remote control handset.
3. Press the RECALL button on Remote control handset to memorize the data.
The data of adjustment item, 323 is changed to "00" after all memory IC's data are initialized.
4. Press AC power switch to turn off the TV set.
5. Press AC power switch to turn on the TV set.
Result : The memory IC, I002 is initialized.
6. After initialization, set the shipping data will be displayed.
7. Go to previous page and adjust the IIC data as in Table below.
IIC ADJUSTMENTS
Most of the adjustment items in the V3AR chassis are controlled by IIC. Adjustment items include video chroma IC (I001, UOC) control, sound multiplex ICs, horizontal & vertical deflection and others.
To start the IIC adjustment, first turn off AC power switch. Press and hold down the TV/Video local key and then press the power switch. Release both buttons after the Service Mode display appears on screen.
Most of the adjustment items in the V3AR chassis are controlled by IIC. Adjustment items include video chroma IC (I001, UOC) control, sound multiplex ICs, horizontal & vertical deflection and others.
To start the IIC adjustment, first turn off AC power switch. Press and hold down the TV/Video local key and then press the power switch. Release both buttons after the Service Mode display appears on screen.
To select the adjustment items
(e.g. RGB level, sub-brightness level etc…), press the Up or Dn cursor button
on Remote control handset. To adjust the data of selected item, press Left or
Right cursor button on Remote control handset .
After completing the adjustments, press the RECALL bottom on Remote
control handset to memorize the data.
Press MENU button or turn off the TV set to end the IIC adjustment.
Press MENU button or turn off the TV set to end the IIC adjustment.
Schematic - Full
