PMI8998 Power IC for Galaxy S8/S8+

When a Galaxy S8 or S8+ comes into your shop completely dead, or charging but not booting, the PMI8998 is one of the first suspects on the board. This IC sits next to the main PM8998 PMIC and handles charging control, boost regulation, and secondary power rails feeding the Snapdragon 835 chipset. Board-level technicians treat these two chips as a pair, since a fault in either one produces overlapping symptoms and confuses beginners who jump straight to CPU or NAND repair without checking power first.Galaxy S8 and S8+ units that suffered a drop, a liquid exposure, or a bad charging habit often develop a short on the PMI8998 rail. You will see this on your bench as a phone that draws current on the power supply but never lights the screen, a unit stuck at 0.00A with no current draw at all, or a board that heats up fast near the power IC cluster the moment you connect the battery. Before condemning the board, isolate the PMI8998 rail with your DC power supply and check for a dead short. If the short clears after removing this IC, you have confirmed the fault and the chip needs replacement, not the whole board.This is a WLCSP/WLNSP-packaged surface-mount component, meaning it sits flush on the board with no visible legs, similar to other Qualcomm PMICs like the PM8998 and PMI8996 used across Snapdragon 835-based devices. Removal demands a hot air station set to a controlled temperature profile, flux, and a steady hand, since overheating nearby components on a densely packed Galaxy S8 board is a common mistake for less experienced technicians. Reballing before reinstallation is standard practice, whether you use a matching stencil or manual ball placement, since reusing the original balls without reballing raises the risk of cold joints and repeat failures.Once the new PMI8998 is seated and reflowed, always recheck the board on your DC power supply before reassembling the phone. Confirm normal current draw on boot, verify charging response with a known-good cable and charger, and let the board run for a few minutes to rule out a thermal-related short that only shows up once the chip warms up. Skipping this step is how "software marna" gets tried on a board that actually needed a hardware fix, wasting time on a phone that was never a software issue to begin with.This chip is also relevant when you are troubleshooting network issue, display problem, or hang on logo complaints that turn out to be power-rail related rather than tied to the specific subsystem the customer described. A full power-rail diagnostic with your multimeter and DC supply before ordering parts saves you from stocking the wrong IC and keeps your repair turnaround fast, which matters when a service center in your city is waiting on a same-day fix.Genuine PMI8998 chips sourced from verified suppliers reduce the callback rate compared to unmarked or relabeled stock circulating in the local market. Confirm the exact revision printed on the chip before ordering in bulk, since Galaxy S8 and S8+ boards across different production batches have used slightly different PMI8998 revisions, and mismatched revisions can cause charging inconsistencies even when the board otherwise boots normally.