Speculation about the existence of this so-called "Sony timer" emerged in the 1980s and 1990s as consumers grew increasingly suspicious of Sony devices that stopped working just after the warranty expired. According to the theory, Sony's time-activated kill switches are designed to boost sales by driving consumers to purchase replacement parts, repairs, or new models (often the cheapest option) after a scheduled period.
Today, decades after the rumors began, people still talk about the Sony timer. In 2006, after a string of laptop explosions prompted a global recall of rechargeable lithium-ion batteries manufactured by Sony Energy Devices Corporation, Japanese Internet forums were flooded with sarcastic comments raving about how effective the latest generation of Sony timers had become.
Clearly, much of the speculation about hidden Sony timers is tongue-in-cheek, but some people appear to take the claims seriously, pointing to the suspiciously precise timing of product failures as evidence of foul play. Regardless of whether or not Sony timers actually exist, the company has been dogged by the perception that its products break down just outside warranty.