1.To avoid the unfold of virus from the firmware, that may induce damage to the ANTMINER S19 collection, the setting function of “Secure Boot” has been switched on and also the “Root Authority” function is disabled. In case you haven't gained your refund nonetheless, make sure you Test your Paypal https://antminer-bitmain-s19-pro62344.bloguetechno.com/the-ultimate-guide-to-bitmain-antminer-l7-69686789