We have a 2 node cluster both on 2012, they were both working fine until a restart where one of servers started becoming unresponsive, when connected remotely or directly on the server you could use PowerShell from the server manager window, if you attempted to press start or click on a desktop icon the system came completely unresponsive, from PowerShell you can open control panel and task manager, and a few other things. eventually we rebuilt the server to save on troubleshooting time. but unfortunately yesterday we had a power cut and to save UPS power we moved the roles on to one node and powered one off, upon the restart it has the exact same issues. this is the Server that was rebuilt only 3 weeks ago, no updates were done, the node will not take any roles when using failover cluster manager from the other server which has the accept same configuration.
any ideas? i'm happy to rebuild again but not sure its solving the issue.