The adapter recognizes the monitor but it only comes on at low resolution. Anytime i select a higher resolution the screen goes black. This is an old cinema display so I thought hdcp off is the one i needed. Thanks in advance for any advice.
Are you connecting directly to the Thunderbolt 3 port of the MacBook Pro? The CAC-1510 cannot do 2560×1600 from a USB-C dock unless the dock has a built-in MST Hub.
The Apple 30″ Cinema HD Display supports only two modes with specific timings:
1280×[email protected] 49.306kHz 71.00MHz h(48 32 80 +) v(3 6 14 -)
2560×[email protected] 98.529kHz 268.00MHz h(48 32 80 +) v(3 6 37 -)
(front porch, sync width, back porch)
Check the timings with SwitchResX.
Any modes that are not 1280×800 or 2560×1600 will need to be a scaled mode.