Which VidCard? Brand, Declaration ROM sticker info, PCB ©date? Another Mac for testing?
Hopefully it's not chicken/egg time:
https://68kmla.org/forums/index.php?/topic/9157-peripherals-links-project-rev-30/&do=findComment&comment=96711
Set your adapter up for 640x480 VGA and see. That's usually the least common denominator for any NuBus VidCard manufactured in the VERY late 80s/early 90s with the notable exception anything from inside the Infinite Loopiness.
I cannot stress this enough, EVERY Mac collector needs to source a MultiSync CRT for testing purposes before they all make their way into the dumpster in the sky, 17" is a good compromise for size, preferably made by anyone BUT Apple.
