Apple has acknowledged that the NVIDIA GeForce 8600M GT video processor found in some MacBook Pro models is defective and the company is offering to replace those chips for free. The defective chips have caused problems that include distorted or scrambled video, or no video on built-in or external displays.

MacBook Pro models that are eligible for the repair program include the 2.2GHz and 2.4GHz 15-inch MacBook Pro, the 2.4GHz 17-inch MacBook Pro, and the early 2008 model MacBook Pro. The affected computers were manufactured between May 2007 and September 2008.

MacBook Pro owners with qualifying machines that are experiencing video-related problems should make an appointment at the local Apple Storeis Genius Bar, of contact an Apple Authorized Service Provider. Apple is also issuing refunds to customers that have already paid for repairs.

Do this to verify which video chip your MacBook Pro uses:

• Choose Apple menu > About This Mac.
• Click More Info in the About This Mac dialog to launch System Profiler.
• Select Graphics/Displays in the Contents column on the left side of the window.
• Look for the Chipset Model in System Profileris information panel.

Use System Profiler to see which video card your Mac has.

Apple will replace the defective NVIDIA GeForce 8600M GT chips in qualifying MacBook Pro models for two years after the date the computer was purchased even if it is out of warranty.

[Thanks to setteB.IT for the heads up.]