MAX77804 Power IC

Power management ICs sit between the battery, the charging circuit, and every rail that feeds the CPU, display, and RF sections of a phone. When this chip fails, the board usually goes dead, stays stuck on the logo, or refuses to charge no matter what battery or cable you try. The MAX77804 is the PMIC Samsung used on the Galaxy Note 3 family and select Tab S and Galaxy S5 boards, and it's one of the more common short-circuit culprits technicians run into on these motherboards.You'll usually land on this chip after a shorted-battery-line diagnosis. Hook up your bench power supply, watch the current draw spike or the board pull excessive amperage with no display response, then trace the short back to the power IC footprint using a thermal camera or freeze spray. On Note 3 boards specifically, a shorted MAX77804 is a well-known dead phone cause after liquid damage or a bad charging attempt with a faulty cable. Technicians dealing with dead after flash symptoms should rule this chip out before assuming the CPU or eMMC is at fault, since a shorted power rail can mimic a corrupted flash in how the device behaves on the bench.Replacing this IC is a BGA-level job. You need a hot air rework station set to the correct temperature profile for the board's other components, flux, a stencil sized for the MAX77804 footprint, and either fresh solder balls or a paste-and-reflow approach depending on your shop's preferred method. Preheat the board evenly before touching the chip itself — Note 3 boards have components close to the PMIC footprint that can lift or shift if your hot air nozzle isn't focused. After removing the old chip, clean the pads thoroughly, check for lifted pads or bridged traces under a microscope, then reball and reflow the replacement.This is not a chip you swap blind. Confirm the fault with proper diagnostics first — a current-limited bench supply reading combined with thermal imaging will tell you within minutes whether the power IC is actually the short, rather than a capacitor or a different rail component nearby. Technicians who skip this step and jump straight to a chip swap often end up doing the job twice.Once installed correctly, the board should power on normally, charge without excessive current draw, and pass through the standard boot sequence without hanging. If the phone still won't power on after the swap, recheck your reflow joints under magnification before assuming the chip itself is defective — cold joints on BGA replacements are the most common cause of a "new chip, same problem" callback.Stock this IC alongside your ISP pinout tools and reballing kit if you handle Note 3 and Tab S motherboard work regularly. It pairs naturally with a hot air station, a stencil kit, a microscope for post-reflow inspection, and a bench power supply for the initial short diagnosis — the same workflow tools you'd already have on a PCB repair bench.