Hi Marcos, Thanks for using the Cisco Small Business community. Blinking Green status means default settings IP Address is assigned: "...When the switch is using the factory default IP address, the System LED flashes continuously. ..."
Have you tried setting your PC IP Address on the Ethernet port in accordance to the guidelines: [ If the switch is using the factory default IP address of 192.168.1.254, you must chose an IP address for the computer in the range of 192.168.1.1-192.168.1.253 that is not already in use.]??
You could be running into a hardware issue, but I would suggest trying again to connect a PC with a functioning Ethernet module to a port on the switch, configure the PC to IP address in Range of 192.168.1.1 - 192.168.1.253 (subnet mask 255.255.255.0) and see if that get's you in. If not, Contact your Seller or the Cisco Small Business Support (http://www.cisco.com/cisco/web/solutions/small_business/small_business_support_and_resources.html)