Built in obsolescence is made into some electronics, this is done by building in a circuit that will activate after the warranty has expired. The way to do this is done with a yearly timer built into the system. There is a cheap modem that is renowned to expire after the warranty is over by some days. Even very expensive computer controlled machine tools will fail with the owner having to call in experts to rectify the timer and reset the circuits all at your cost.
Electronics do not fail with out a reason. Early radios are running for years and never fail this is because they don't have the built in failure programme in them.
Motor car manufacturers warrant there product for three years or more, ever wondered why?