L520 Dispalyport to hdmi conv, video and sound problem on TV

[Van GORRE]

HI

I have L520 and this cabel http://www.molex.com/molex/products/fam ... troduction, so i make it's write on instruction to get video and sound on TV; but i have only video, sound isn't work. In screen/sound config/option i dont have option to change "make as defalt".
My cabel is wrong or something?
Can I buy that http://www.ebay.pl/itm/150829933141?ssP ... 911wt_1044cabel converter?