回答“Reseated RAM, blank screen, beeping every 5 secs. tried everything ...”This is a response to an old thread, but it still may be helpful to some. For MacBooks running Intel chips, there is essentially no difference between Mac memory and memory for one of the many brands of Windows laptops. Yes, you have to get the 204 pins, the speed and the voltage right, and I am not sure if 1xR8 memory will work OK in a MacBook, or whether 2xR8 is necessary. I guess I’ll have to find out, won’t I? Apple made the shrewd decision to use commodity SODIMM memory, then obfuscated by claiming that the memory had to be especially for the Mac. This is no different than Windows laptops, whose brand-name companies put brand name stickers on the memory to make it special and more expensive.