Products with an STK anything are likely shorted! Those Hybrids from Sanyo/Panasonic/Matsushita were some of the worse things ever made. Most of those chips were highly unreliable and destructive to overcurrent.
Lots of audio amplifiers met an early demise from those ICs, and alot of projection TVs used STKs and they failed too. Anything with an STK in it died. the STKs used in power supply regulators, also failed.
Garbage....