Hello everyone, I have a problem with my Bally space invader pinball machine. When I start the game it automatically just tilts and wount kick the ball out. The till on the playing field is the one with the problem. On the switch test number 7 constantly flashes which indicates tilt switch . the one on the door works, both cabinets are working. Disconnected the switch on the playing field made no difference ,looks like the mpu itself is causing the problem. If I unplug the J2 connector (looks like the color code) off the mpu still tilt out. Any suggestions?

In test mode , door slam is working and plum Bob is working. If I unplug J2 it still showing tilt # 7 switch. That's why I'm why. I'm thinking it's the mpu. Going to ohm it tonight. I'll keep you all posted on my results thanks for your help if it is the mpu what circuit is on the playing field tilt. Looks like the top wire is white with a red stripe like the one on the playing field schematics I have don't show the Tilt switches. Does anybody have a wiring schematic flow chart with the tilt on them?

When I originally check the machine out the board has been repaired by someone else ,the gentleman had it for 3 days and then it tilted out and hasn't played it . when I got there the driver selenoid board was short ,l repaired the driver solenoid board now all the pop bumpers and everything works in test mode but still have the tilting problem

Yep, it's the mpu

All fixed, when I pulled the mpu board off and check the back of the J2 connector I noticed somebody replace the pins and they accidentally solder two together.cleaned up the sodder and know more problem. I want to thank everyone for their help and support.

Next weird problem with a Mata Hari, picked up a Mata Hari not working mpu board did absolutely nothing sent it out. Get the board back now it's flashes seven times and machine goes on ,no chimes and all the Plainfield solenoid start ratcheting when the game resets. Put it in selenoid test mode everything works but don't match the numbers according to the schematic sheet in the back box and does not operate the top out hole or ball kicker. Swapped out the driver board, does the same thing, test all the transistors and can get everything to work by grounding them, Chimes ,solenoids ,Etc. Is it possible the eproms are damaged? According to the number on them they are the right ones for the board. If I hit everything with my hand the game scores properly drop targets reset but ratchet pop bumpers are firing two at a time and also it does count down the bones right. went through all the wires on the playing field everything is in perfect shape no shorts no wires missing or crossed. What next?