Your issues sound somewhat similar to mine. I did the SD card reset. It works, but the machine seems to like me messing around with it less and less, because the "can't browse to machine IP" issue happened again relatively quickly.
How to do a SD-Card reset? Seems I have a bricked KnCMiner...
Hello,
I seemed to have that problem in early January. Following the guide here
http://forum.kncminer.com/forum/main-category/hardware/23664-how-to-restore-a-broken-beaglebone-without-the-need-to-rma really helped me out.
If you have a mac you don't need to get an Ubuntu Live USB/CD, if you don't have a mac or linux PC then you need to get the Ubuntu Live USB/CD to format the micro-sd card.
Also make sure you micro-sd card is under 4 GB (Tip: Radioshack does not have them, Walgreens does though)
Best of luck getting it back up and running!