iMac won't boot from SATA or USB (Can't find startup disk)
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 appears
- The 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 reset
- Internet 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!
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 culprit
- I have a new SATA cable installed into the iMAC, but the same symptoms persist
- The 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 disk
- In 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.
Is this a good question?