Chosen Solution
Hello,
My 2012 iMac Intel 27" EMC 2546 is not working correctly.
I purchased the SSD upgrade kit and I cannot get it to boot. Below are the symptoms: iMac does not show any disk in Startup Manager (holding Option at startup)In recovery mode, the SSD is visible, but is not recognized as a startup disk. Verifying the disk shows everything is ok.If the iMac is turned on without pressing any keys, the flashing question mark folder appearsThe SSD does not work internally (connected to the SATA cable) or externally (connected by USB in the enclosure).The old HDD was wiped but also cannot be read from the SATA or USB connection Here are the steps that I’ve taken to remedy so far, without any luck: Checked to ensure that the SSD was properly formatted. I verified its functionality by externally booting on a 2012 MBP and a 2012 iMac 21”. Everything is working correctly (running Mojave). Additionally, the enclosure and temp sensor are working correctly.PRAM reset multiple times. Additionally, removed some RAM and changed the slots, and then went through the PRAM reset again.SMC resetInternet recovery through startup manager This iMac was donated to me from work and was wiped before being given to me. Could this be a culprit? My only other thought was the SATA cable to the board, but I’m not sure why it wouldn’t boot via USB. Any help is much appreciated. Thanks! Update (10/12/2019) An update to this: I purchased a SATA cable and when through the SATA Cable replacement guide here on ifixit. Everything has gone smoothly, but I still have this issue persisting. Just to recap: I have a new 2.5” SSD purchased from ifixit that is formatted correctly and has Mojave installed on it. This SSD is 100% working correctly as I’ve been using it with another 2012 iMac (through USB). I have ruled out the SSD as the culpritI have a new SATA cable installed into the iMAC, but the same symptoms persistThe iMac powers up, but will show the flashing question mark folder (this is with the SSD plugged in internally to the SATA cable)In recovery mode it does not detect the diskIn disk select (pressing option on startup) it only shows ‘internet recovery’The mac was wiped before it was given to me; could this be the culprit? Thanks in advance.
On an external drive, any format will work. But internally it must be APSF or GUID to be seen. Is this a blade drive or a 2.5” drive? Can you give us a link to what you bought.
On a boot up hold cmd R Go into utility next go to disk utility select erase them format. It should now come up in the system.
