One.To avoid the unfold of virus while in the firmware, which often can lead to damage to the ANTMINER S19 series, the setting function of “Safe Boot” is switched on along with the “Root Authority” operate is disabled. A 180-working day guarantee interval is delivered starting from the delivery date. https://emilioggwsk.blog2freedom.com/34521395/detailed-notes-on-antminer-bitmain-s9