Nvidia said that any replacement costs Apple incurs will be covered by the $196m fund it announced in July. "In a way, this is all old news to us," said Derek Perez, an Nvidia spokesman.
Apple said contrary to what it had been told by Nvidia several months ago, some MacBook Pro laptops equipped with Nvidia's GeForce 8600M GT graphics processor may be among the machines using flawed chips. Apple cited an internal investigation as the source of its information.
"We've been diligent in our analysis with Apple, as with all our OEM partners," said Perez. "Our analysis is that failure in a MacBook Pro is remote, but Apple is going to decide its warranty or replacement procedures based on their own quality guidelines."
Nvidia first publicly reported a problem with an older generation of its graphics processor in "significant quantities" of laptop PCs, in July. At the time, the company said it would take a $150m to $200m charge against revenue to cover anticipated repair and replacement costs.
More than a month later, Nvidia booked a $196m £114m) charge against its fiscal second-quarter results.
"At that same time, Nvidia assured Apple that Mac computers with these graphics processors were not affected," Apple said. "However, after an Apple-led investigation, Apple has determined that some MacBook Pro computers... may be affected."
Hewlett-Packard has confirmed that the bad Nvidia chips were used in 24 different HP Pavilion and Compaq Presario notebook models, while Dell has identified 15 models in its Precision, Latitude, Inspiron, Vostro and XPS lines. Both HP and Dell have issued BIOS updates designed to boost fan speed. The Nvidia chips fail at higher-than-normal rates because of overheating; the increased fan speed is intended to ward off failure of the graphics processor.
NEXT PAGE: Free repair for those affected
Apple has confirmed that a number of MacBook Pro laptops manufactured last month may contain faulty Nvidia graphics processors.
HP and Dell have also extended warranty periods for the laptops with the bad chips, and in some cases have offered free repair.
Apple essentially announced the same yesterday. "If the Nvidia graphics processor in your MacBook Pro has failed, or fails within two years of the original date of purchase, a repair will be done free of charge, even if your MacBook Pro is out of warranty," the company said.
The company's hardware warranty is normally one year from the date of purchase, although customers can purchase extended support plans.
Perez said that the $196m charge Nvidia took two months ago would cover the additional cost of any reimbursement to Apple. "Yes, Apple falls under that amount," he said.
Both 15in and 17in MacBook Pro models are included in the potential free repair. The symptoms, said Apple, include no video, or distorted or scrambled video. Only MacBook Pros with the GeForce 8600M GT processor manufactured between May 2007 and September 2008 are affected, the company said.
However, all MacBook Pro models now for sale on Apple's online store still contain the GeForce 8600M GT processor.
Customers can take their laptops to an Apple retail store or authorised dealer for evaluation and repair, or call one of the company's support lines . Users who have already paid to have their MacBook Pro's video fixed will be issued refunds.
Last month, Nvidia was hit with a lawsuit that accused the company of violating US securities laws by concealing the existence of the chip defect.