@psims Im going to try this. Sometimes, my mid-2012 13” MBP turns on but man, I better not even look at that thing or move it ever slightly or press hard on the touchpad or keyboard because it will freeze, turn off, and do the three beeps when I try turning it on. I just took it apart yesterday but minimally and did some cleaning and stuff and put it back. It turned in and was working but when I pulled out this USB stick, it turned off and I get three beeps again.
To confirm, do these three beeps have anything to do with the disc reader on the left when flipped upside down or is it the RAM cards that people keep referring to here? I have a bone stock MBP.