I bought an oscilliscope. Where would the best place to look for noise be? I have a 2 channel model. where would I hook up the scope leads?

Electrical noise is generally one or a series of relatively high amplitude and very fast spikes appearing on an input to the BOB or controller. These spikes are often so fast that it requires a pretty high quality scope to be able to spot them so don’t be surprised if you find nothing. Scope probe connects to an Input and it’s Screen to GND. Measurements should be taken whilst the machine is in operation so take care.

The best bet with electrical noise problems is to fit miniature 0.1uF capacitors (one connected between each used Switch Input and GND) at the controller / breakout board end.

Tweakie.

Addition;  Just a suggestion but another thing that has caused problems is the Watchdog Timer – Config / General Config – Make sure ‘Use WatchDogs’ is unchecked.