Those 2 tests are to just bypass the throttle. If you have total loss of main battery power, which your description sounds like. You've got a different issue.
The first thing that comes to mind is having a good battery connector connection. Check for voltage coming out of it on the controller side if possible. Or even across the connectors for presents of a voltage drop.(which would be bad) Your first job is to get the LEDs lit back up... ;) If all is good going into the controller. Time to turn to the harness. Using this wiring pin-out diagram, check for main battery + power coming out of the controller.
(https://i.imgur.com/3OLenvz.jpg)
Battery + and Battery negative. Should show full battery voltage. Continue with the rest of the harness if needed.
Let's keep this thread going here in the Pie discussions... if needed.
Regards,
T.C.