> never seen a  burnt out newer ICU.  Now, I've tried replacing that BD438
> transistor and  have had no luck.  Maybe there are other components on the board burned
> out  on the ones I tried, don't know, so I gave up experimenting.  Looks like
>  the ball is in your court.

There is also a "snubber" diode across the output of that transistor, so
that could go bad as well. I have not yet traced the circuit back to see
what other components could go bad, but I'll get to it eventually.

Jon