If you're choice is the ebay route, first only deal with trusted sellers (laptopaid, macrecycling are good sellers) and don't hesitate to contact the seller BEFORE buying the logic board to ask him to confirm that the logic board is fully functional (all ports working) and ask if the 2 ram slots have been tested. If something goes wrong then you'll have the seller's confirmation email that will help you to get a seller or a Paypal refund.