On Monday, August 26, 2019 at 9:03:07 AM UTC-7, wrote:
On Monday, August 26, 2019 at 11:09:15 AM UTC-4, John Robertson wrote:

And if this is the case, a TO-92 package, 15+ V regulator is he

https://www.newark.com/on-semiconduc...-1a/dp/42K1178

Same source for a 15- V regulator as well.

Peter Wieck
Melrose Park, PA
One more step you can take in an attempt to verify this hypothesis: you might remove the remaining epoxy from the chip and look at it under a microscope. I have seen some chips with part numbers in one of the metal layers. Or you could see that it is too complex to be a simple transistor and complex enough to be a regulator, or something in between like a Darlington.