This study aims to analyze the reliability of the power supply system at the Sibolangit TVRI Transmitter Station which uses Uninterruptible Power Supply (UPS) with a capacity of 40 kVA and 250 kVA as an important component in maintaining the operational continuity of the transmitter. A reliable power supply system is crucial to ensure broadcast quality and prevent service disruptions due to power supply failures. The methods used in this study include collecting UPS operation data through field monitoring, analyzing technical parameters such as Mean Time Between Failure (MTBF), Mean Time To Repair (MTTR), Availability, and comparing the performance of the two UPS units. Data were analyzed using statistical approaches and reliability engineering tools to evaluate the performance and failure patterns that occurred during the observation period. The results show that the 250 kVA UPS has a higher level of availability than the 40 kVA UPS, with an average MTBF value of XX hours and YY hours, respectively, and MTTR of AA hours and BB hours. The analysis also reveals the main factors that affect reliability, including the quality of the electricity supply from PLN, load conditions, and the implemented maintenance schedule. These findings provide technical recommendations regarding load management, improved preventive maintenance schedules, and risk mitigation strategies to improve power supply continuity, particularly for low-capacity UPS units. Thus, this study contributes to the understanding of power supply system reliability in broadcasting installations and provides a basis for planning for improving operational performance at the TVRI Sibolangit transmitter station.