Max77705C Power IC

Every Samsung technician eventually runs into a board that charges intermittently, drains fast, or shows a battery percentage that jumps around without reason. In most of these cases, the fault traces back to the PMIC — and on a huge share of Samsung Galaxy boards, that PMIC is the MAX77705C. Maxim Integrated designed this chip as a companion power management IC with a built-in Type-C interface, and Samsung adopted it starting with the S9 generation, carrying it forward through S10, S20, S21, S22, S23 FE, several Note models, and the Z Fold/Flip line.What makes this IC different from a basic charging controller is how much it consolidates onto one die. It runs the battery charger, the fuel gauge (the circuit responsible for reporting accurate battery percentage), the MUIC block that identifies what's plugged into the Type-C port, safe LDOs for smaller power rails, plus the haptic motor driver and notification LED driver on boards that route those functions through it. When this chip degrades or takes moisture/short damage, you don't just lose charging — you can lose fuel gauge accuracy, Type-C detection, or haptic feedback depending on which internal block failed.On the repair bench, this shows up in familiar patterns. A board plugged into a charger that shows no charging icon, no current draw on your power supply box, or charging that starts and drops randomly usually points here first — especially after you've ruled out the charging port and flex cable. Battery percentage stuck at a fixed number, jumping erratically, or a phone that shuts down at 20% instead of 0% is a fuel gauge symptom tied directly to this IC. Type-C not being recognized by PC or charger, despite a good port and cable, is a MUIC-side fault on the same chip. Some boards also lose haptic vibration or LED notification when this IC is the point of failure, since those drivers sit on the same package.Because the MAX77705C sits on the motherboard as a BGA component, replacement is a reballing and hot-air job, not a simple solder swap. You'll want a good preheater, a reflow station capable of handling BGA reballing profiles, flux, and a reliable reballing stencil sized for this package. Boardview reference and a decent microscope help confirm pad condition before you commit to removing the old chip, since lifted pads or damaged traces around this IC are common on boards that have already been through amateur repair attempts. After reballing and remounting, always test charging current, fuel gauge readout, and Type-C detection together — a board can pass one test and still fail another if the reflow wasn't even across all four sides of the package.This chip is stocked for technicians doing genuine board-level work: reballing services, motherboard repair shops, and service centers handling Samsung water-damage or drop-damage cases where the PMIC is confirmed faulty through diagnostics rather than guesswork. If you're doing software-side troubleshooting — FRP lock, pattern unlock, or software marna cases — this IC isn't your fix. It's strictly for hardware fault cases where charging, battery reporting, or Type-C detection point to PMIC failure on the board.