Lenovo is recalling more than 50,000 of its PCs due to a possible fire risk. The 2010 ThinkCentre M70z and M90z both house a defective component in their power supplies that can overheat. Worse still, the power units are embedded within these all-in-one models and so are not readily replaceable. The manufacturer is arranging appointments to fix the power supply problem. Fire-averse customers can double-check all the details at the source below.