Shield TV Bootloader

In the original Shield TV, within the bootloader, we could move between and select options by touching the power button. How can we do this in the new Shield TV 2017 since it does not have a power button?

should be able to use X/Y/A on controller… BUT controller stops working when I enter bootloader. No way to select.

Instructions from nvidia don’t seem to work:
https://nvidia.custhelp.com/app/answers/detail/a_id/4359/~/how-to-invoke-the-android-fastboot-menu-on-shield-tv