✔ 最佳答案
One long & three Short beeps on start up :
Video card problem. No VGA (video) card detected. If
you are hearing this beep code while having no VGA cards installed and
system still refuses to output any display with card installed, it simply means your VGA card is not functioning as it should.
To confirm problem, try:
1. Remove card. Brush to clean the slot and also the contacts of your video card. Reseat card properly then reboot.
2. If no help, borrow a similar video card from your friend to replace yours and reboot.
If yours is proven faulty, replace it.
參考: My PC Know How & Asus website.