Your scanner may have some hardware faults.
你的掃瞄器可能有硬體上的問題

You can call Benq for a technique support.
你可以打電話給benq詢問

Or take it to Benq directly and ask the engineer to check the scanner.
或直接帶到BENQ維修點請工程師檢查

u8526425, thank for your reply,
My scanner brought at last year Aug,
so now just over warrantly.

If can i hope can avoid any payment
and try to DIY.

接到另一台電腦上看看，先確定是掃描器的問題。

I recommend to call Benq for a offical help.
真的很建議打電話去benq問

That wo'nt take too much time , and fixing the scanner may not cost you too much money.
這並不會花費太多時間
送修scanner也不一定會花太多錢

It's quite hard to tell you some other way to solve your problem on the internet, and "Good luck" is the only thing I can tell you.
而我們在網路上很難以其他方式去替你解決這問題
我也只能祝你幸運

If you are using USB port to connect Benq scanner, please forget about the on board USB port (USB support from VIA or Nvidia chipset is faulty). Probably you will need to buy a USB 2.0 daughter board (NEC chip set is more compatable). Since you bought the scanner last Aug, it is impossible to ask the original seller to replace it. So. this will be the best thing I could suggest.

If a new USB 2.0 card doesn't work with Benq, you probably need to buy a new scanner. Well, go for those name brand products (e.g. HP. Agfa ... little expensive, or Umax, Microtech .... almost perfect .....Mustek is less reliable .... as to the rest product I have no comment). I had bad experience with Benq scanner too, finally it was replaced with a Microtech.

Good luck

Thank for everyone suggestion,
yesterday i try to open and check
than very lucky my scanner is working now.