Thanks for any ideas as to what would cause this combination of events. Have not yet tried mixing and matching to see if I can get 3 GB total memory to work, etc. Is it possible something happened to the slots when I tried to reseat the memory that would cause 2GB to fail but 1 GB to work? Having trouble believing that the Crucial memory went bad and the new PNY memory is also bad and only the original memory is good, or that I failed to properly seat either set of the 2GB sticks but properly installed the 1 GB sticks.ĭid something change recently (say, within the past month) that could cause 2 GB sticks to be an issue? Question: what am I missing? I could believe the memory came loose or the Crucial memory went bad. For 29/mo, we provide access to advanced level technicians who will answer your questions on any Macbook board related matter to the best of their knowledge promptly & walk you through how to solve your problem so you can deliver a working board to your customer. Tried replacing the memory with two new 2GB PNY memory sticks. 820-3332-A MacBook Pro Retina 15' A1398 No display 3 Beeps Rossmanngroup Forums. Suddenly, the beeping and fails to start. I replaced them with two 2GB Crucial memory sticks (model limited to 4 GB memory). It had two 1GB Samsung memory sticks in it.

Trying to understand what happened in my situation.

I've searched the forum and learned that the 3 beeps at start up indicate no good memory banks found.

Macbook pro 3 beeps in a row