DIAGNOSIS The unit is detecting an open safety switch, most likely because the basket isn't fully seated. The three-beep error is a common fail-safe.
FIX Pull the basket completely out and re-insert it with firm, even pressure until you hear a definitive click. Don't just slide it in; you need to push it past the initial resistance. Wiggle the handle slightly as you push to ensure it's perfectly aligned. The display should reset.
IF THAT DIDN'T WORK Check for food debris or grease on the basket's rim or inside the unit's basket slot. Even a small piece can block the sensor. Unplug the unit, let it cool, and wipe both contact areas clean with a damp cloth.
HEADS UP Never force the basket. If it won't click in after cleaning and proper alignment, the latch mechanism inside the unit may be jammed or broken—contact support.