Your evidence tells me you have a defective card. I would contact the seller with this info and ask for advice. If that fails, ask the seller for a refund or a replacement card. Don't let them string you along - you have only 30 days to file a claim with PayPal if it comes to that. And if you didn't pay with PayPal, well in Vegas they call it "rolling the dice".
"I hv tried with & without connecting the molex(power connector) with motherboard (supplied with the card) bt nothing except it just ruined(burnt) one of my 8gb pendrive." What do the instructions say? If that molex connector is mandantory and not an option, you may have (inadvertantly) destroyed the card and your pendrive. If that is the case, it wouldn't be right to give the seller a hard time. Just buy another card (I see a lot of these on eBay are under $10), hook it up the right way and hope that it works. Good luck with your project.
Is it internal or external USB 3.0 PCI expansion card? It could be due to faulty ports or incompatibility problem despite the driver is been installed without error.
hmm u r right..bt refund the card is more difficult for me as ebay is not directly available in my country.Jst waste of money
Molex is not mandetory for all device bt you know usb 3.0 gives extra power charge for operation bt not as extra that burns that device It's my bad luck..nothing else.
I buy things on eBay regularly and it is not available in my country . This should be an advice to you when next you are going to buy anything from the online market. Look for sellers with good rating, at least 99.4%, read the reviews on the negative feedback and check if he ships international. Those information really helps to spot somebody who would listen to you and help to make thing easy.