Daewoo DV-K784N-JJ, Service Manual

Page: 45 / 128

44
2. PIF & INPUT SELECTOR
1) Outline
The circuit to tune proper signal of broadcasted radio frequency (RF: VHF, UHF) and to demodulate it to baseband signal for record. It
is composed of two parts, TMI and Input selector.
The former makes RF signal changed to composite video signal and audio signal, and the latter selects line input and RF input.
* Refer to "PIF & INPUT SELECTOR BLOCK DIAGRAM" and "PIF & INPUT SELECTOR SCHEMATIC"
2) The name and function of pins on TMI (Tuner/Modulator/IF)
* REFER TO TMI BLOCK DIAGRAM
3) The name and function of Pins on Switching IC (MC14053B) 2/4 Head Only
Section NO. Pin Name Function
1 AUDIO INPUT MODULATOR AUDIO INPUT
2 CH-SW RF OUTPUT CHANNEL SWITCH (3CH: OPEN, 4CH: GND)
RF
3 MB MODB (+5V)
MODULATOR
4 CONTROL MODULATOR OUTPUT SW (ON: VCR MODE, OFF: TV MODE)
5 VIDEO INPUT MODULATOR VIDEO INPUT
6 BP TUNER PLL IC +B (+5V)
7 BT TUNER +B (+32V)
8 PLL CLOCK PLL CLOCK SIGNAL INPUT
TUNER 9 PLL DATA PLL DATA SIGNAL INPUT
10 PLL ENABLE PLL ENABLE SIGNAL INPUT
11 N.C N.C
12 N.C N.C (IF OUTPUT TEST POINT)
13 +B IF CB (+9V)
14 AUDIO OUTPUT AUDIO SIGNAL OUTPUT
15 GND GND
16 AFT AFT DETECT OUTPUT
17 N.C N.C (IF AGC MONITOR POINT)
18 VIDEO OUTPUT COMPOSITE VIDEO OUTPUT
IF (INTER
MEDIATE
FREQUENCY)
NO Name Function NO Name Function
1 INPUT Y1 LINE VIDEO 9 CONTROL X TUNER ‘L’
2 INPUT Y2 N.C 10 CONTROL Y LINE ‘H’
3 INPUT X1 LINE AUDIO 11 CONTROL Z
4 OUTPUT X AUDIO OUTPUT 12 INPUT Z2 TUNER VIDEO
5 INPUT X2 TUNER AUDIO 13 INPUT Z1 LINE VIDEO
6 INHIBIT INHIBIT 14 OUTPUT Z VIDEO OUTPUT
7 GND GND 15 OUTPUT Y LINE VIDEO
8 GND GND 16 VCC 9V