We had exactly the same problem with couple of 7914s.
We upgraded our CCM from 3.3(3) to the 4.1(3), and "lost" a couple 7914 (about 5%). Some of them were recovered by connecting to another phone, but a couple was completely dead. The same simptoms as you describe - first you have one steady light, then second line starts blinking, and after a couple seconds you have two green lights and nothing on the screen. We played with upgrading/downgrading a phone load, sidecard load, even connected to an old "testlab CCM". Nothing helped. Finally we got these cards replaced by Cisco through RMA.
Cisco Voice, CCNP, CCDP, CCSP, MCSE W2K, Security+, etc.
I'm not able to access my old voice mail messages all of a sudden. The recording says something like 'the message is currently not available'. This has never happened before in all the years I have been using this system. I have t...