Always verify the full part number and suffix, as minor variations in the "NU" or "AJZS" codes can impact specific pin functions. KBC1126-NU SMSC Keyboard Controller LQFP-128
If the laptop won't turn on (no power trigger) or the keyboard and touchpad are entirely unresponsive, this chip is a likely culprit. kbc1126nu datasheet patched
Since the chip lacks internal flash, you can swap it with a new one from eBay or specialized parts suppliers like RefixTool without needing an I/O programmer. Always verify the full part number and suffix,
The SMSC KBC1126-NU is an industry-standard Keyboard Controller (KBC) and IC primarily found in HP and Compaq laptops from the Ivy Bridge era (e.g., HP EliteBook 8570w, 8560w, and ProBook 4530s ). Its primary responsibilities on a motherboard include: HP EliteBook 8570w
If you are repairing a laptop and suspect a faulty KBC1126-NU, keep the following in mind:
Scanning the key matrix and processing interrupts for user input.
Controlling cooling fans based on internal temperature sensors.