Topic Title says it. Not all the time but I hit one, two, or three drop targets and then the captive ball and the machine will tilt.
This does not happen all the time in that order of sequence but it will tilt only when the captive ball hits the target. Hmmmm and its a new replacement mpu and had the same issues with the old mpu. Any ideas where to pin point??? I have already started changing a handful of diodes and looking at switches.

Ok I have tested more and when the drop target closest to player (number 1) is down it will tilt when captive ball hits target.

Im thinking the diode on the #1 drop target. captive ball wont trigger tilt unless that 1 target is down?

its called the clone chamber! have not done any work to the machine, I have owned it for over a year and all has been working fine.

Seem to have fixed it I just replaced all the diodes on row of the clone chamber http://www.pinitech.com/switch_database.php?name=Bally_Space_Invaders&printview=1