fix power-down on nexus
fix power-down on nexus

lamassu/lamassu-machine,evan82/lamassu-machine,evan82/lamassu-machine,lamassu/lamassu-machine,evan82/lamassu-machine,evan82/lamassu-machine,bitstopco/lamassu-machine-old,lamassu/lamassu-machine,bitstopco/lamassu-machine-old,bitstopco/lamassu-machine-old,bitstopco/lamassu-machine-old,lamassu/lamassu-machine