PowerEdge M620 NIC problem with OS

Hi community, we have a little problem with one of our blades and I can't find a similar case over the net.

We have a M620s running  in a M1000e with Scientific Linux, all run good but few days ago the OS can't recognize the NIC, and the blade stay isolate, but the Blade Center show everything is OK. We run Scientific Linux on all our blades without problems, our version control and kernel is good, the other blades with the same configuration run well, we changed the network daughtercard (NDC) 2 times but the problem persists. Any idea? some references or suggestion to ask on google or anywhere. Thanks.