Hi all, I have a late 2015 5k iMac. When I first purchased it I replaced the stock 8 gigs of RAM with 32 gigs of crucial memory. It's definitely overkill for what I do, but it was cheap enough so I figured why not. Last night my iMac froze up. Force quit wouldn't do anything so I ended up having to do a hard shut down. When I turned it back on all I got was a black screen. I tried booting to safe mode but continued to get a black screen. I did a bit of research and determined it could be an issue with the RAM. I took out all of the crucial RAM, replaced it with the original Apple RAM and sure enough it booted right up. So, I'm thankful I have my computer back, but now I'm not sure what to do. Would it make sense that one faulty stick would cause the boot problem? I'd like to have as much RAM as possible in my iMac, but I'm not sure if I should experiment to try to find out which stick is faulty. I'm wondering if anyone has had an issue similar to this with aftermarket RAM, and what they did to fix the problem. Any advice would be much appreciated!