If this card is based on the TB6560, you'll possibly need some fixes to get the board working reliably. Apart from general noise and grounding issues, and some issues with the opto's and logic level translation on a lot of these, the chip itself has a peculiar power up/down sequence that most designers don't adhere to, which makes them prone to blowing the IC's. If you google "tb6560 fixes" you'll see what I mean.
What are you intending to use it on? And more importantly, what steppers/PSU are you planning on using in conjunction with it?
cheers, Ian