It died. At the price of a new mower it was cheaper to replace than fix.
Same thing happened to my string trimmer when I began using it last summer. The 87 octane 10% ethanol/gas mixture I had used in it for the last 3 or 4 summers had ruined the carburetor and the price of replacing the carb made it more practical to just buy a new trimmer. Now I pay $.90 per gallon more for ethanol-free gas, but it should save me money in the long run if it prolongs the life of my new (almost) Echo trimmer.