Best thing to do is send it to Partserve in Edenvale,JHB. http://www.partserve.co.za/warrantydetails.php?id=3. I think they are still the official RMA partner for Sony Playstation.
My 1 year old PS3 slim had an issue with the blueray drive not reading disc's very well. Had it swapped out within a week and never had a problem since, had my new one for over a year now.