Who's the manufacturer and what's the model number of your stove.
The vast majority of problems I've found with these units is the actual connection to the inductive heating element.
Check the induction coil connections and make sure they're making good contact. (WITH THE UNIT UNPLUGGED< NO POWER).
I'd also be checking (WITH THE CIRCUIT BREAKER TURNED OFF), the power socket outlet itself. The socket contacts may be so worn that you have intermittent contact.
Power socket outlets experience wear over time, and the socket manufacturer may not make the best quality sockets.