Diagnosis
The membrane under the touchpad is likely failing or has moisture/debris under it. This is a common point of failure on these units.
How to Fix It
First, completely unplug the blender. Get a soft, slightly damp cloth (not wet) and thoroughly clean the entire control panel. Dry it completely. Sometimes a sticky film from smoothie spills can interfere with the capacitive touch. Plug it back in and try with dry fingers.
If That Didn't Work
If specific buttons (like 'Pulse' or 'High') are dead while others work, the issue is internal. The control panel is a single sealed unit. There's no user-serviceable fix here; the whole base would need warranty service or replacement.
Heads Up
Avoid using chemical cleaners on the touchpad. If moisture got inside the unit from a spill, it could short the control board, which is a more serious repair.