Did you ordered form bitmain or any 3rd party reseller ?
Sometimes you have to wait 15-20 minutes till the L3+ connecting to the pool and start hashing ..
Did you get a error msg on the System / overview tab like " Socket connection failed " ?
I suspecting you might have a psu problem , or the BB Board or IO Board went bad ...
I did order from a 3rd party seller. The unit does not power up, the controller doesn't seem to be working properly. The seller agreed to a refund (thankfully).
Thanks for your feedback.