Looks like your power. I used to do electronics and a robot that started doing weird things (stuttering, basically not taking instructions) was misdiagnosed with almost every problem in the book, until we realised that the battery was below specced voltage...
I'm betting the when the SA powers up, it suddenly draws too much current which kills the dying battery (and the SA), which then causes the SA NOT to draw power, causing a cycle which looks like flashing lights or stuttering.