So my TIP 102 arrived and I replaced Q5 which had decided to lock on the pop bumper. Finally got the machine up and running, played a few test games and then something odd started happening - when the ball hit the standup targets, if it touched the rivet in the centre of the target it would do one of 4 things depending on which target was hit.
1. Fire a pop bumper and lock it on causing the fuse under the play field to blow.
2. Tilt
3. Cause the machine to reset, as if it had just been turned off and back on
4. fire a slingshot.

I tried a couple of things
- closing the standups with my finger - worked normally
- closing the standups with the ball touching the plastic target - worked normally
- closing the standup with my finger and then touching the ball to the rivet - did one of the bad things above
- Closing the standup with the ball touching the rivet - did one of the bad things

It's intermittent, sometimes it doesn't do this, and works completely normally, othertimes it does.

I've run out of 1A slow blow fuses now, so can't do any more testing.

I'm thinking I'll just replace the standup targets and see if that stops it. Unless anyone else recognises this behaviour and knows what is causing it.

I need to put a new connector on J3 on the solenoid board as somtimes the board doesn't initialise and there are low voltages at TP 6 and 7 and on tensioning some of the wires at J3 this sorts itself out - so I don't know if this bad behaviour could have anything to do with that?

I'll try and upload a video that I took of this stuff.

Thanks all

Ok. Will do. Thanks again.