Hook up a game machine to the monitor and see if the problem persists.
The VGA port responds differently than the RGB port. Had problems with an older a3000 in respect to the video ports.
VGA screen went funky through the VGA port, hooked up an old RGB monitor without problems.
Also have a CEI A1962 RGB monitor that didn't display when recived it in shipping. Took the monitor case off to look around. Reattached the connector that goes onto the back of the CTR.
