UPS (Uninterruptible Power Supply) repair and service involves diagnosing and fixing faults to ensure the unit provides reliable backup power. This includes inspecting and replacing worn-out batteries, which are the most common failure point. Technicians also check internal components like capacitors, fans, and circuit boards for damage, test the inverter and charger circuits, and calibrate the unit. Regular servicing prevents unexpected failures, extends the UPS's lifespan, and maintains its ability to protect connected equipment from power disruptions.