How to enter service mode to Akira 14THHS TV using IC UOC OM8370 IC - OM8370 pin details
- Press [menu] key → display picture menu
- Press digital key “6” “4” “8” “3” → display “M”
- Push [standby] key one time to exit factory mode and return to normal.
TO SELECT MENUS IN FACTORY MODE
In factory mode {“M”
mode) there are ten menus totally. Menu 1 to Menu 4 can be selected directly but
Menu 5 to Menu 0 must be select by these steps:
- Press “CALL” key, to call “M”.
- Press “LOCK” key, then press any one numeric key from 5 to 0.
IC : OM8370 / TDA9340 / TDA9347 PS N3 BLOCK DIAGRAM [UOC]
PINS AND FUNCTIONS
Pin 1 Standby control,
“1” is on, “0” is off.
Pin 2 SCL
Pin 3 SDA
Pin 4 Tuning PWM output
Pin 5 Auto AV control SW,
connected with the SCART 8th
pin. Input.
The rising edge or the falling edge operates.
Pin 6 Key board input.
Pin 7 Volume
Pin 8 Mute control, “1”
is mute, “0” is off.
Pin 9, Pin 12,
Pin 18, Pin 30,
Pin 35, Pin 41,
Pin 55
GND
Pin 10 BAND 1 control
output.
Pin 11 BAND 2
Pin 13 SECAM PLL,
connected with a capacitance (no use in this type).
Pin 14 +8V power source
supply
Pin 15 Using a capacitor
of 220n in series to GND. This pin decouples the internal digital supply
voltage of the video process and minimizes the disturbance to the sensitive
analogue parts.
Pin 16 Phase-2 control
loop, this pin requires a capacitor at 2.2nF © in series to GND.
Pin 17 Phase-1 control
loop filter connected to pin 17 is suitable for various signal conditions like
strong /weak and VCR signal. This is achieved by switching of the loop filter
time constant by changing the Phase-1 output current.
Pin 18 GND
Pin 19 Bandgap
decoupling, the bandgap circuit provides a very stable and temperature independent
reference voltage. This reference voltage (4.0V) ensures optimal performance of
the analogue video processor part of the OM8370 and is used in almost all
functional circuit blocks.
Pin 20 East-west pillow
signal output.
Pin 21, Pin 22 Vertical
drive output.
Pin 23, Pin 24 IF input.
Pin 25 Reference current/
This pin requires a resistor to ground. The optimal reference current is 100mA
which is determined by this resistor. The 100mA reference current should not be
changed because the geometry processor is optimized for this current.
Furthermore the output current of vertical drive and EW are proportional to this
current.
Pin 26 Vertical sawtooth.
This pin requires a capacitor to ground of 100nF.
Pin 27 AGC output. This
output is used to control (reduce) the tuner gain for strong RF signals.
Pin 28 Audio de-emphasis.
Pin 29 Sound decoupling.
This pin requires a capacitor connected to ground. The pin acts as a low pass
filter needed for the DC feedback loop.
Pin 30 GND
Pin 31 Sound loop filter.
Pin 32 AVL filter
Pin 33 Horizontal drive
signal output, needs a resistor in series to +8V.
Pin 34 Sandcastle output
/flyback input.
Pin 35 External audio
input, this pin should be grounded in this chassis.
Pin 36 EHT tracking /over
voltage protection. If something is wrong, the anode high voltage rise the
heater voltage will rise too. When the rising voltage arrive some limit, the
V406 works, the voltage of pin 36 will exceed 3.9V. The OM8370 will stop working.
Pin 37 PLL loop filter.
Pin 38 CVBS output.
Monitor or RF videos can be selected.
Pin 39 +8V supply source
Pin 40 CVBS input
Pin 42 Y signal input
Pin 43 C signal input
Pin 44 Main audio output.
This pin is connected to the TDA9859.
Pin 45 RGB signal input
blanking.
Pin 46, Pin 47,
Pin 48
RGB signal input.
Pin 49 ABL. It means been
current limiter input. R410 is the control resistor.
Pin 50 Black current
input from the CRT board.
Pin 51, Pin 52,
Pin 53
RGB drive signal output
to the CRT board.
Pin 54 +3.3V
Pin 55 GND
Pin 56 +3.3V
Pin 57, Pin 58,
Pin 59
12MHz crystal.
Pin 60 Reset. NC in this
chassis
Pin 61 +3.3V
Pin 62 NC
Pin 63 This pin is
connected to the HEF4094. Functions expending.
Pin 64 IR signal input.
