Williams High Speed (Williams, 1986) wont do 3 ball multiball

[SteelHorse]

hi just got this machine couple days ago and have noticed during the chase the left ramp hideout does not lock the ball in place. What it does is kick it out and if the right ramp hideout has one locked already then only a 2-ball multiball starts. Any ideas why it's not locking? did switch test and all ok. Or could this be normal as I can't remember as it has been years since I playeed. Also when the High Speed game is on the lights make a loud humming and buzzing noise, how do you disable this annoying buzzing from the lights when game is not being played? Jeff