200 HPDI stalls when trimmed down, sometimes.

[bert.herr]

My 2002, 200hp Yamaha HPDI has stalled on me several times recently. This happens when I use the down trim button. When this happens, I also loose the ability to trim up or down and the starter does not work. My depth finder still works and the battery conections are clean and tight. I keep turning the key to start the engine and it eventually starts and everything is fine. This does not happen all of the time. I think it has only happened while I am backing out of my boat slip.

Any ideas on how to trouble shoot this?

Thanks,

Bert