ViewSonic N3250wb-1G, Service Manual

Page: 24 / 82

1.5. TV receiving test:
1.5.1 TV SIGNAL TEST ITEM
CENTRALISM TRANSMITTING SIGNAL CHECK CONTENT
SET CONTENT
CHANNEL
ORDER
FREQUENCY
(MHz)
PATTERN SOUND P/S(dB)
CHECK
CONTENT
P0(PAL I)
45.75 MONO SCOPE FM Mono
(SWEEP TONE)
-5 ELECTRIC
ABNORMITY SOUND
P1(SECAM L)
55.75 COLOR BAR
Nicam Stereo*2
-10 SOUND ,PICTURE
P2(SECAM L)
160.00 MONO SCOPE FM Mono*1
(400Hz)
-10 NOISE LIMITED
SENSITIVITY
P3(PAL D/K)
440.25 Full White 100% Nicam Dual -10 SOUND,PICTURE
P4(PAL B/G)
471.25 Dem Nicam Stereo*2 -16 STEREO FUNCTION
P5(PAL I)
603.25 MULTIBURST Nicam Dual -10 DUAL FUNCTION
P6(PAL B/G)
855.25 Color Bar Nicam
Stereo*2
-10 SOUND,VIDEO
P7(PAL D/K)
863.25 MONO SCOPE FM MONO*1
(400Hz)
-10 NOISE LIMMITTED
SENSITIVITY
TV TEST METHOD
A.P0 Examines sound by ear, whether the sound does have mechanical resonation and the
electrical unusual sound, and image to sound disturbance.
B.P1and P6: Check sound and picture.
C.P2: Examines whether the sound does receive the image disturbance, Judgment basis: Whether
there is unusual sound, input signal LEVEL<=36dBu,and STEREO SENSITIVITY is normal.
D.P3: Under main/sub/main-sub mode, check sub function.
E.P4: Examines whether the sound does receive the image disturbance, Judgment basis: Whether
there is unusual sound.
F. P5:Check T1 of close-caption. Input signal level<=45dBu.
G.P7: Adjustment attenuator, If the critical point of the change of the image signal to noise ratio is
under LEVEL<=60dBu, regards as normally.
TIMING TABLE (FACTORY PRESET MODE) (TABLE 3)
ITEM
1 2 3 4
TIMING
640
*
480@60HZ 640
*
480@75HZ 800
*
600@60HZ 800
*
600@75HZ
Pixel Rate
25.175MHZ 31.500MHZ 40.000MHZ 49.500MHZ
H TOTAL
31.778us 26.667us 26.400us 21.333us
H DISPLAY
25.422us 20.317us 20.000us 16.162us
H B-Porch
1.907us 3.810us 2.200us 3.232us
H Width
3.813us 2.032us 3.200us 1.616us
H Border
0.318us 0.000us 0.000us 0.000us
V TOTAL
16.683ms 13.334ms 16.579ms 13.333ms
V DISPLAY
15.253ms 12.800ms 15.840ms 12.800ms
V B-Porch
1.049ms 0.427ms 0.607ms 0.448ms
Vs Width
0.064ms 0.080ms 0.106ms 0.064ms
V Border
0.254ms 0.000ms 0.000ms 0.000ms
H/V Sync
-/- -/- +/+ +/+
Interlace
No. No. No. No.
ITEM
5 6 7 8
TIMING
1024
×
768 60HZ 1024
×
768 75HZ 1280
×
720 60HZ 1280
×
768 60HZ
Pixel Rate
65.000MHZ 78.750MHZ 74.250MHZ 65.000MHZ
H TOTAL
20.677us 16.660us 22.222us 20.677us
ViewSonic Corporation
Confidential - Do Not Copy
N
3250
w
b
-1
G
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