ViewSonic N4261w-1M, Руководство по обслуживанию

Страница: 14 / 77

D.
POWER OFF Mode
Κ
i. After POWER ON procedure finished, the signal of Keypad and remote control will transform to
PW328 for further processing. U41 chip did not handle the signal of Keypad and remote control any
more. When the system receives the power off order by Power Key of remote control or Power
ON/OFF of the keypad. Firstly PW328 will send current screen status to memory U30 via I2C bus,
then the PWRDOWN I/O port of PW2030 will send a Hi signal to U48 closing the Switching power .
R301 1K
R299
10K
POWER OFF=Lo
U41
SM5964C40J
RST
10
XTAL2
20
XTAL1
21
GND
22
PSEN
32
ALE/PROG
33
EA/VPP
35
VCC
44
P1.0
2
P1.1
3
P1.2
4
P1.3
5
P1.4
6
P1.5
7
P1.6
8
P1.7
9
P2.0/A8
24
P2.1/A9
25
P2.2/A10
26
P2.3/A11
27
P2.4/A12
28
P2.5/A13
29
P2.6/A14
30
P2.7/A15
31
P3.0/RXD
11
P3.1/TXD
13
P3.2/INT0
14
P3.3/INT1
15
P3.4/T0
16
P3.5/T1
17
P3.6/WR
18
P3.7/RD
19
P0.0/AD0
43
P0.1/AD1
42
P0.2/AD2
41
P0.3/AD3
40
P0.4/AD4
39
P0.5/AD5
38
P0.6/AD6
37
P0.7/AD7
36
PWRDOWN P{9}
V5up
V5up
R357
10K
V5up
C483
100U
1
2
Q11
MMBT3906
3
2
1
Antenna Circuit:
Tuner (TUV1236D) has two RF inputs. Left was the connector of Terrestrial input ; Right was the connector of CATV
Input.
A.
Terrestrial Input Connector
Κ
Connects to your ATSC antenna and receives broadcasting signals. There are two signals ; Analog TV
(NTSC signal) and Digital TV (ATSC signal) could be received.
z
Analog TV
ΰ
NTSC signal
α
Tuner TUV1236D receive the signal come from RF NTSC signal Δ Selects desired channel and
demodulate image composite signal (signal mark T1CVBS) by pin 14 of Tuner output to U18 PW328
decoder via path C174 and audio SIF signal (signal mark T1SND) by pin15 of Tuner output to U27
MSP4440K via C322 for demodulating MTS/SAP of Digital TV signal (ATSC signal) .
Tuner TUV1236D receive the signal come from ATSC signal Δ Selects desired channel and converts
analog signal into MPEG Transport Stream via Tuner TS1( Transport stream TS1DATA0-TS1DATA7)
bus into U29 PWM2030 to separates MPEG video and AC3 digital audio .
ViewSonic Corporation
Confidential - Do Not Copy
N4261w-1M
11
All manuals and user guides at all-guides.com