Lime SDR USB Connecting Problem

Dear all
We bought a LimeSDR USB. I started to cnnect and run by LimeSuite GUI
Unfortanlty at the begining I got a probel in LED. two of the are ok. But the one related to FPGA is flashing red and other related to user defind is off.
I tried several time several scenarios I reinstal LimeSUuite GUI in mac, I tried by USB 2 and 3. I tried by using power adabptor 6V 500 mA.
But stil it has the problem.
Please help me to sovle this problem