Sony has said some of its Vaio laptops are equipped with faulty graphics chips from Nvidia, which the graphics company has said could cause some laptops to overheat and ultimately fail.

The PC maker is offering free repairs and extended warranty on certain Vaio models with Nvidia graphics chips made of faulty die and weak packaging material. Sony is the latest addition to a growing list' of PC makers carrying faulty Nvidia chips, including Apple, Dell and Hewlett-Packard.

A user will know their Vaio model is affected if a laptop shows distorted video, duplicate images or a blank screen due to failure of the Nvidia chip, the company said on a support Web page.

Sony will cover the cost of repair. The PC maker is also providing an extended three-year warranty in addition to the standard 12-month warranty. No refunds for the laptops are being offered by Sony.