I loaned a standby/extra driver I keep on hand for emergency repairs to a "friend" to test his cnc lathe.
Well he returned it saying that it did not work, just kept flashing the leds both red and green together.
I then went and looked at his machine, he had the pwr supply hooked up backwards, so he blew my driver.

Does anyone know what parts are damaged when this happens? I do not want to loose $90 because a jerk
who will not replace it blew it up?

I have done a visual insp of the board and components and can not find anything physically damaged or burned.

Thanks for the help

David