I'm having this problem at the moment myself. My friend and I are gonna try and solve the problem tomorrow. It seems like there is a lot of trouble shooting involved with the crane/deadworld.

My friend and I got my crane working last night (have dead world mod), had to adjust the interrupter disk below the play field and also the middle shaft on the crane that adjusts the up and down movement. One thing that I found out though was if it it works 3 times in a row in test mode you should be fine for game play. What was happening during the unload globe test was that the crane took off the first 3 balls in a row just fine, but it wouldn't pick up a 4th ball, so after hours of fiddling my friend and I tried playing a regular game and the multiball worked fine after multiple games. Pretty amped that its working again. However - now my led lights on my crane mod aren't working....damn, if anyone knows how I should go about fixing the lights let a brotha know!