Service manual

6
ViewSonic Corporation Confidential - Do Not Copy VA503b-2_VA503m-2
5 ELECTRICAL REQUIREMENT
Horizontal / Vertical Frequency
Horizontal Frequency 30 – 62 kHz
Vertical Refresh Rate
50 – 85* Hz.
* When the resolution is set to 1024 x 768 , the vertical refresh
rate may be up to 75 Hz; for other resolutions, the vertical refresh
rate may be up to 85Hz.
Maximum Pixel Clock 80 MHz
Sync Polarity
Independent of sync polarity.
Timing Table
Primary Presets
1024 x 768 @ 60Hz
User Presets
Number of User Presets (recognized timings) Available: 10 presets total in FIFO configuration
Changing Modes
● Maximum Mode Change Blank Time for image stability: 3 seconds (Max), excluding “Auto Image Adjust” time.
● Under DOS mode (640 x 350, 720 x 400 & 640 x 400), it should recall factory setting when execute “Auto Image
Adjust”.
The monitor needs to do “Auto Image Adjust” the first time when a new mode is detected. (See section “0-Touch™
Function Actions”)
Item Timing Analog
1 640 x 350 @ 70Hz, 31.5kHz
Yes
2 640 x 400 @ 70Hz
Yes
3 640 x 480 @ 50Hz
Yes
4 640 x 480 @ 60Hz, 31.5kHz
Yes
5 640 x 480 @ 67Hz, 35.0kHz
Yes
6 640 x 480 @ 72Hz, 37.9kHz
Yes
7 640 x 480 @ 75Hz, 37.5kHz
Yes
8 640 x 480 @ 85Hz, 43.27kHz
Yes
*3
9 720 x 400 @ 70Hz, 31.5kHz
Yes
10 800 x 600 @ 56Hz, 35.1kHz
Yes
11 800 x 600 @ 60Hz, 37.9kHz
Yes
12 800 x 600 @ 72Hz, 48.1kHz
Yes
13 800 x 600 @ 75Hz, 46.9kHz
Yes
14 800 x 600 @ 85Hz, 53.7kHz
Yes
*3
15 832 x 624 @ 75Hz, 49.7kHz
Yes
16 1024 x 768 @ 60Hz, 48.4kHz
Yes
17 1024 x 768 @ 70Hz, 56.5kHz
Yes
18 1024 x 768 @ 72Hz, 58.1kHz
Yes
19 1024 x 768 @ 75Hz, 60.0kHz
Yes
*1. Tolerance ≧ ± 2kHz.
*2. Any timing not in the list, it should display as normal or show on “OUT OF RANGE” OSD message
without blanking.
*3. The image quality of 85Hz mode might be worse than 75Hz.