why cannot detect 250G HD (in usb enclosure)?

I got a Newman 3.5 inch usb enclosure, it used to be runing a 120G seagate HD, fine no problem, but when I put a new 250 G seagate hd in, the computer won't find in window.

I took out the 250 g hd and put inside the desk top machine, it is fine and I made 3 partician on the 250G hd.

I ring seagate, they told me it is the enclosure box problems....

send email to newman, their email is jamed and bounce back.

any one who has the clue?  

紐曼大靈通3.5T

紐曼大靈通3.5T移動硬碟盒3.5寸






產品功能：


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鋁鎂合金外殼，最新霧銀表面處理，美觀耐磨

獨特的直接硬碟供電，數據安全可靠

超小結構設計、攜帶方便可內裝各種3.5寸IDE硬碟

USB2.0高速介面，最高傳輸速率達到480Mb每秒，並向下兼容USB1.1

獨特電源介面，杜絕電源反查問題

外置電源全部通過3C認證
http://www.usb-mp3.com/ArticleShow.asp?ArticleID=141 [:435:]

It is possible: 1.the max of your enclosure limited at 200GB. 2. try to use extra-power supply if you didn't try it yet.
Anyway, the 1st is more possible.

thanks!

if anyone in Beijin can ring Newman to ask them the question, it will be clear out.

cannot understand they do not have a email to take the feed back of the customer, I will not buy their product any more.