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 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.

Nvidia last year reported some graphics chips were overheating due to faulty material and the thermal design of some laptops. The overheating could cause laptops to fail, the company said at the time.

After the disclosure, Dell, Hewlett-Packard and Apple offered either a BIOS fix or free replacements for laptops with faulty chips. On Web sites like HP Lies, customers are still complaining about PC makers not offering free repairs for models that may be affected by the faulty chips.

The issue has also taken a toll on Nvidia's earnings. The company has taken more than US$300 million in charges to cover warranty and product replacement costs. Last week Nvidia took a $119.1 million charge during the second fiscal quarter of the year, while it recorded a $196 million charge a year earlier.

The issue applies to these specific Sony Vaio models with Nvidia graphics chips: VGN-AR1xx, VGN-AR2xx, VGN-AR3xx, VGN-FZ1xx, VGN-FZ2xx, VGN-FZ3xx, VGN-FZ4xx, VGC-LT1xx and VGC-LT2xx.

The story was first reported by enthusiast Web site Semiaccurate on Monday.