ZMA Oceanic Controller reported radar and communication equipment failures led to a loss of non-radar separation between multiple aircraft. The reporter noted this is a recurring issue and needs to be repaired without delay.

Narrative

While on shift; I returned from a break and was immediately assigned to handle traffic between sectors 58; 63; and 62. During this time; the radar system malfunctioned; causing a complete loss of radar coverage. As a result; all aircraft targets were in coast track; and I had no visibility of the aircraft's actual positions. To complicate matters further; the communication frequency also went out; leaving me unable to establish contact with the aircraft. This combination of equipment failures led to a loss of non-radar separation between multiple aircraft; significantly increasing the risk of potential conflict.Recommendation: Given the recurring equipment failures in the ZMA ocean sector; it is evident that the airspace is operating in an unsafe condition. The reliance on single-thread operations; particularly in high-traffic situations; significantly compromises the safety of both air traffic controllers and aircraft. The recent incident; where radar and communication systems failed simultaneously; demonstrates the critical risk to non-radar separation and overall situational awareness.The continued refusal by the Command Center to adjust traffic flow through this known failure-prone airspace exacerbates this safety risk. This lack of proactive action is putting lives at risk. In its current state; the airspace remains a significant hazard; and if these systemic issues are not addressed immediately; there is a real and imminent threat of catastrophic outcomes; including potential collisions and loss of life.It is imperative that the necessary repairs and operational changes be implemented without delay. If these issues are not urgently corrected; the probability of an accident leading to the loss of aircraft and personnel will only increase. The safety of the flying public and air traffic controllers must be prioritized; and decisive action is required to prevent a tragedy.