Hi John G.,

I believe you are describing the MC-60 board. I can tell you that,
visually and electronically, it is a completely different animal. My
board has only one heat sink that goes down one side of the board.
Screwed to that decent radiator is a single FET and a High Powered
Diode of some sort.

Thanks for the help, but repairing an MC-70 with notes on an MC-60 will
be helpful, but it's probably not going to get me to the finish line.

The big Identifier of an MC-70 is two large black ELNA electrolytics
sitting next to a one big mother of a brick-cased rectifier, and a heat
sink that runs the length of one side of the board.

Here is a link to a page displaying the MC-60 and the MC-70 boards.
Maybe this will help others help me.

http://www.treadmilldoctorstore.com/...-Electronics_5

Thanks to John G. for trying,
John