2012 Imac 27, 16GB, Core i7, Nvidia GeForce GTX 680mx 2 GB connected to Samsung Syncmaster 305t.
Connecting Imac to Syncmaster with Dual-Link DVI Adaptor (Apple A1306).
SyncMaster Cycles through standard color screens and does not recognize the connection. Apple does not recognize the SyncMaster.
This setup previously worked.
Suggestions?