Laptop u201cAC Adapter Wattage/Type Cannot Be Determinedu201d

Lenovo and others show “wattage and type cannot be determined” when the ID pin / one-wire chip in the tip is unread—wrong brick, damaged cable, or port corrosion.

Fixes that work

1. Reseat the tip firmly; try a known genuine adapter of the correct wattage.
2. Clean DC jack lint (power off).
3. Try a different cable if detachable.
4. BIOS update only from the vendor if the jack and brick are known good.

Safety notes

Undersized chargers that “work” will throttle performance and still throw warnings—match or exceed original wattage.

FAQ

Third-party bricks?

Many lack the ID chip—warning stays even if it charges.

Battery not charging?

Could be battery or EC; warning alone is the ID path.

Photo: Unsplash. Repair steps are general guidance—model variants differ. Unplug power and follow ESD-safe practice before opening devices.