MT6358VW Power IC

Every MediaTek-based smartphone motherboard depends on a single chip to keep every other component alive: the PMIC. The MT6358VW is that chip on boards used in the Redmi 9, Oppo A9, Oppo A91, Oppo A79, Oppo A3, and Vivo Y5s. It sits between the battery and the SoC, converting raw battery voltage into the multiple regulated rails the processor, memory, and RF sections need to boot and stay running.When you get a dead phone that shows zero current draw on your DC power supply, or a board that pulls current but never boots past logo, the PMIC is one of the first suspects on a MediaTek board. A shorted or degraded MT6358VW can pull the whole board down, cause a reboot loop, or leave the phone stuck in a boot loop with no display response. Technicians working these boards know the drill: isolate the short with thermal imaging or a current-limited bench supply, confirm the PMIC rail is the culprit, then reball or replace the chip.MediaTek designed this PMIC family around a WLCSP package with roughly 194 balls, built for tight board space in compact phone designs. It communicates with the baseband processor over an SPI control interface, using dedicated SRCLKEN control lines to sequence buck converters, LDOs, and internal drivers during power-up. This handshake protocol is what gives MediaTek platforms their controlled, staged boot sequence rather than one indiscriminate power dump. The IC is rated for operation across -30°C to +85°C, which matters in Pakistan's summer workshop conditions where board temperatures climb fast under hot air rework.For technicians running box software (UMT, CM2, Miracle) alongside hardware diagnostics, understanding the PMIC's role helps separate a genuine hardware fault from a software-side "dead after flash" situation. If the phone draws current but the software tool can't detect the target, check PMIC rail continuity before assuming a CPU or eMMC fault. A lot of "dead phone" jobs that get escalated to CPU reball turn out to be a simple IC change once the PMIC rail is confirmed faulty.Reballing this part requires a matching stencil, quality solder balls, and controlled hot air temperature — going in cold or overheating the pads is the fastest way to lift traces on these small-format boards. Preheat the board evenly, use flux generously, and keep your hot air nozzle centered to avoid shifting neighboring components. After IC change, always recheck short/continuity on VBAT before powering the board, since a bad reball can reintroduce the same short you just fixed.This listing is for the MT6358VW chip only — genuine BGA part, not a generic universal replacement. It's stocked for technicians who need a direct swap rather than a bench-level substitute, keeping your repair turnaround fast for walk-in customers with dead or reboot-looping devices.