bench testing a PE+ monitor

[puckhead]

got a PE plus with a bad monitor. flyback on chassis was bad, crackling with a bad smell, i replaced the flyback with one i had from another chassis that was NG.  now it powers right up, good anode voltage, screen makes your arm hair stand up on start up.  however, no image on the bench. i turned the flyback all the way up, there are no raster lines. on shutdown, i get the brief horizontal while line. i hooked up a signal generator ( cga) , i get nothing. i read that igt bastadized the RGB and sync to make it prorietary? it a long drive to the game to just pop it in and try it. do i have options?
thanks