Led video processor has witnessed the birth, growth and development of led display. It is also the most important facility for led display. The quality of led video processor have a direct effect on display effect of full color led display. Binding led video processor and display together makes it convenient for terminal users. So that full color led display can be used widely. As for full color led display technicians, it is necessary to know the common problems and solutions to video processor.
1. Cannot see a full screen of image on full color led display: full color led display can not deliver the whole image of input signal, only display part of it.
Solutions: a. Setting the value of “output width” for video processor is same as pixel of led display width, the value of “output height” is same as pixel of led display height.
b. If the input signal is computer signal, setting the video process to “full screen” effect.
2.VGA input, the image deviates: while choosing VGA input signal, the image deviates from vertical or horizontal position.
Solutions: a. choosing VGA input and keep to display VGA signal.
b. Make sure the signal which enters VGA input port is free from disturbing, and signal amplitude is meeting requirements.
3. The image is in the center of full color led display, no “full screen” effect.
Problems: a. while choosing computer input signals (VGA, DVI, or HDMI etc), the processor is set correctly, but the image is in the center of led screen.
b. The value of output resolution for computer video card is set differently, but the value of input resolution for led video processor is fixed, for example, the value is always 2048x1152_60Hz.
Causes: The receiving ports of VGA, DVI or HDMI contains EDID datum.EDID datum have ports which could identify the information of all resolution formats and best resolution format. After connecting to VGA, DVI and HDMI ports of the processor, the output resolution of the computer video card will be output by default to the best resolution format that the processor can recognize. The resolution set by the computer video card is only displayed the resolution of the effective image, and displayed in the center.
Solutions: reset the output zoom value of video cards VGA/DVI/HDMI to “full screen”. It is found that the setting is different during operation according to different video cards, different operation systems, even same operation system of different versions. Following is the step of how to set video cards with XP and Win 7:
a.Win XP operation system: As for notebook of NVDIA+INTEL dual video card, right click the blank area on the desktop, then there is a pop-up menu. Select “Graphics Options” → “screen adaption” → “digital TV” → “full zoom”, then DVI signal is set to output with full screen.
Right click the blank area on the desktop, then there is a pop-up menu. Select “graphic attribute” to enter into intel graphic and media control panel. On the menu of “display” → “general setting”, choose “digital display”, set the “zoom option” to customized aspect ratio, the width and height are set to 100%.
b.Win XP operation system: As for notebook of ATI video card, right click the blank area on the desktop, then there is a pop-up menu, click “ATI control panel”, then click “digital panel(DVI)” → “zoom option”, set the value to “overscanning 0% ”, that is to say the DVI signal is set to output with full screen.
c.Win 7 operation system: As for notebook of ATI video card, right click the blank area on the desktop, then there is a pop up menu. Click “ATI contal panel”, then click “my digital panel” → “zoom option(digital panel)”, set the value to “overscanning 0% ”, that is to say the DVI signal is set to output with full screen.
After connect the video card to led video processor, the audio card can not output sound.
Problems: if connect the computer video card DVI or HDMI to video processor, the audio card can not output sound. But unplug the connecting wires of DVI or HDMI, the audio card can output sound correctly.
Causes: HDMI port could deliver image signals and audio signals simultaneously. Now most video cards support HDMI output. That is to say, even using DVI port, the default setting of video card is to support HDMI. So video card can deliver sound. The sound of computer can be set to deliver from audio card, or from video card. If it is set to use video card HDMI as the default way to deliver sound, when connect the computer video card DVI or HDMI to led video processor, the computer will deliver sound from video card, that’s why audio card have no sound.
Solutions: Set audio card as default way to output sound. As for different operation system, the setting is different. Let’s take Win7 and Vista as example.
Win 7 or Vista: right click on the icon “trumpet” of the taskbar, choosing “playback device”.