UPDATE: I tried once more to disconnect the internal keyboard and connecting a USB keyboard and the scrolling issue seemed to go away - and I was able to OPTION-Boot and boot to diagnostic mode with the USB keyboard. So I did some more digging - actual digging. I dug the down arrow cursor key out and it looked like there was chunk of lint in it. With the key taken apart the machine DID NOT have the issue. I cleaned the key and put it back together and it started scrolling again. I took it apart again and cleaned it better and now I think it works. If it continues to give problems I think I will need to replace the keyboard (top case assembly). Sorry for not recognizing this earlier and thanks for the responses.