Black screen?

I used OCLP 1.4.3 to install latest Ventura on an early 2008 iMac that was running Monterey via an earlier version of OCLP.

The machine is in a bedroom upstairs and is used primarily as a machine to run ArqBackup to push my backups to local NASs and cloud storage.

It is normally remotely managed. I have used RealVNC Connect in the past and things have worked well.

Now when I try to connect all I get is a black screen.

I tried turning on screen sharing and going to VNC://ip-addr. Same result.

Anyone have a clue what is going on?

Dennis