03-04-2018 07:53 AM
I currentely bought 2 sets of 16GB (2x8GB DDR3L - 1866 SODIMM for a ram upgrade of my iMac Retina 5 27inch late 2015. After installing the 32GB of Crucial ram my mac won't boot up anymore. Only once it did but after changing to another useraccount it turned black again. Somehow the problem can't be fixed and I'm out of idea's. Can somebody help ? Curcial ???
I've invested more than € 300 for a ram upgrade that doesn't work. Rip off ? In the mean time I pulled out all of te Crucial ram and changed it back to my 8GB of Apple ram and know there are no problems.
Any help/advise ?
03-04-2018 07:32 PM
Did you order the memory direct from Crucial?
Did you identify the memory needed by using the Crucial Advisor Tool or Crucial System Scanner? Did you use the Crucial part numbers identified to order from a third party? Usually Crucial memory for Apple systems will have "For Mac" printed on them. If not, then the memory may be incompatible with the iMac since there can be other timings that are not shown to us.
Try one new stick at a time in a single slot to make sure both new memory sticks are good.
If both new sticks work Ok in one slot, then try one of them in the other slot so you verfiy both slots works with the new memory.
If neither one work in the one slot, try them both in the other slot.
Make sure the memory is fully seated. Also inspect the gold contacts on both sides of the new memory to make sure they are clean & shiny with just straight scratches on the contacts where the slot made contact.
If you cannot get any of the new memory to work, then try performing an SMC reset and a PRAM reset with the new memory installed. Make sure you hear the chime three times after initiating the reset. Note this will reset your Date & Time plus your Startup Disk preferences which you will need to update after booting.
04-04-2018 11:20 PM
Give a try and install only 2 memory moduls (16GB) first, use the slots, where your original modules were.
I just bought 16GB (2x8) Crucial memory (CT2C8G3S186DM) to my iMac 27" Retina (Late 2015) and I mixed it with 8GB Apple RAM, they work fine together. Unless your modules fault, they should work in your iMac.