PM660L-004-01 Power ic

A PMIC failure rarely announces itself clearly. The phone just won't power on, or it charges but never boots, or it dies again three days after a "successful" repair. That's the kind of fault the PM660L-004-01 gets pulled in for. This is a companion power management IC in Qualcomm's Snapdragon 660-series platform, working in tandem with the primary PM660 PMIC to split up the board's voltage regulation load — one chip can't carry every rail on its own, so Qualcomm designed the 660L to handle a portion of the LDO and switcher outputs that feed the display, sensors, and secondary subsystems.On your bench, this shows up as a dead phone that draws current on the multimeter but never shows a boot logo, or a board that boots into a loop and dies right after the splash screen. Before you commit to changing the IC, check power rail behavior with your test box or bench power supply — a short on one of the 660L's output lines will usually pull current abnormally even with the display disconnected. If you're seeing that pattern on a Redmi Note 6 Pro or Redmi Note 7 board, this chip is a confirmed fit, not a guess.Reballing is straightforward with standard BGA gear — hot air station, stencil matched to the ball pitch, flux, and a microscope for placement. Clean the pads fully before reflow; leftover solder or lifted pads under this IC's footprint cause more comebacks than the chip itself does. Preheat gradually rather than blasting straight to reflow temperature — PMIC packages on these boards are sensitive to thermal shock, and a cracked substrate from rushing the preheat stage turns a fifteen-minute job into a full board write-off.This chip sits in the power delivery chain, not the application processor chain, so don't confuse a PM660L fault with a CPU-side issue. If the board powers up fine but has isolated problems — one specific sensor not responding, or a display backlight rail acting up — that's more consistent with a 660L fault than a full board failure. A complete dead board with zero current draw usually points elsewhere first, so rule out the charging IC and battery connector before you assume this chip.Stock this one if you handle Xiaomi repairs regularly. Redmi Note 6 Pro and Redmi Note 7 boards are common enough in Pakistani repair shops that PMIC-related dead board cases come through often, and having the part on hand instead of ordering per-job keeps your turnaround time down. Pair it with a decent hot air station and a stencil kit sized for this package, and you can turn what looks like a scrapped board into a same-day fix.Keep in mind this is a board-level component repair — it demands steady hands, the right temperature profile, and a clean workspace free of static risk. If you're newer to PMIC-level reballing, practice the removal and placement on a junk board first before working on a customer's device.