Hello guys, Some friend was throwing away a Mid 2010 MBP 15" with a swollen battery, broken touchpad and no power supply. I work with IT and decided to give it a try and repair it because i always wanted to test MacOS by myself instead of someone else's computer. With a new power supply i was able to turn it on and check about the system's health. Everything working good. I had to remove the battery and touchpad. No issues with that. Since the system is working good (it was on 10.10 Yosemite) i decided to replace the 320GB HDD with a spare Kingston's A400 SSD i have. In this process i had to do a fresh install of MacOS 10.13.3 (using APFS) in order to have the EFI and SMC up to date. Everything done successfully. Great! Now its time to upgrade its RAM memory (4GB - 2x2GB). I used 16GB (2x8GB - Kingston KVR16LS11/8@1600Mhz) from my laptop and BOOM! Boot issues. Okay, i cleaned up the PRAM and was able to boot it normally, 16gigs recognized correctly in the system information. Yay! Let's browse a little and check its stabilit -suddenly reboots- I did my research and found out that in the majority of cases like this, its due to a failing memory module. I believe this is not the case because i placed the memory back in my laptop and it works normally. It is also not a hardware/compability issue on the MBP because i was able to run Ubuntu Live (17.10) on it, with the 16GBs of RAM and everything worked fine. For hours. Of browsing. Here's some more tests i did, with no success: Use the memory modules individualy; Safe mode startup; It works with a 4+2GB memory configuration (1600Mhz + 1333Mhz modules); I was not able to run the MacOS hardware test because i dont have the needed DVD and it wouldnt work online either; TL;DR - After upgrading to 16GBs of memory, the system is not stable. It will not open heavy/complex applications beyond the normal (Finder) environment, it suddenly reboots instead. The memory modules are Ok and work in the same MBP hardware running a different S.O. (Ubuntu). I believe this could be a memory configuration on MacOS, something related to the kernel maybe, but i have no ideia how to set it up and found nothing about it online. Do you guys have any ideias about solving this? Could the missing battery be the cause in any way?