ET9640 Charging iC

Charging faults are one of the most common repair tickets that come through a Samsung-focused workshop, and a large share of them trace back to a failed charging IC rather than the port itself. The ET9640, manufactured by EREK in a QFN10 package, sits in the charging control path on several Samsung Galaxy boards and manages how the phone detects, regulates, and delivers power once a cable connects to the port.When this IC degrades or shorts, you typically see one of a handful of symptoms on the bench: the phone shows a charging icon but the percentage never climbs, the battery charges painfully slowly, the device gets warm at the charging port during use, or the phone doesn't respond to a charger at all despite a good port and cable. Before you commit to an IC change, run through the basics first — check the charging port for bent or corroded pins, test the flex cable, and confirm the battery holds a charge under load. Once you rule those out and multimeter readings on the charging line point to the IC itself, the ET9640 becomes your target component.This chip is compatible with a specific set of Samsung Galaxy boards, including the A7, A31, A21s (A217), A52, M12 (M127), A25 (A256), and A52s (A528). Board revisions vary across production batches, so always cross-check the IC marking and pad layout against the board in front of you before reflowing a replacement. A mismatch in pad count or orientation on a QFN package causes bridging or a dead board fast, so this step isn't optional.Reworking a QFN10 part like the ET9640 rewards a controlled process. Start by mapping the orientation of the old IC before removal — a photo under the microscope saves you guesswork later. Use hot air at a moderate, even temperature to lift the failed chip without lifting adjacent pads, then clean the site thoroughly and re-tin the pads with fresh solder paste or a thin layer of leaded solder for a more forgiving reflow. Align the new ET9640 carefully under magnification; QFN packages have no visible leads to guide placement, so pad alignment is everything. A slightly warped placement or a bridge between two of the ten pads shows up immediately as either a dead charging line or a short that pulls down the whole raAfter reflow, don't just plug in a charger and call it done. Check for shorts to ground on the charging line with a multimeter before applying power, then test with a known-good cable and charger. Watch the charging behavior over several minutes — a proper repair shows a steady percentage climb and stable temperature at the IC site, not a flicker that cuts out.Stocking the ET9640 on your bench makes sense if you handle a steady volume of Samsung Galaxy A-series and M-series charging repairs. It's a low-cost part relative to a full charging port or motherboard replacement, and swapping the IC restores full charging function without touching the port assembly. Pair it with a hot air rework station capable of fine temperature control and a decent microscope, and this becomes a routine 15–20 minute repair rather than a guessing game.Keep a few units on hand rather than ordering one at a time — charging IC failures cluster around specific board batches, and having stock on the bench means you're not waiting on a supplier while a customer's phone sits idle.