Stan,
FWIW - The one I bought on eBay worked for a few minutes and then blew the
12v regulator on the video board.  After that - no video or raster.
I replaced it and it's worked fine ever since.  I'm still not sure why it
failed - the 12V regulator tends to run pretty warm/hot based on the
circuit, but I'm not sure if that had anything to do with it.
-Frank