iMac 2017 (Ventura) turns off automatically
Hello! On iMac 2017 (Ventura), spontaneous shutdown occurs periodically, could you tell me if anyone has information about this message?:
iMac (2017 – 2020)
It sounds like one of your internal SATA drives is failing.
Depending on the severity of the failure & how the failure affects the rest of the system, you may be able to install macOS to an external USB3 SSD and boot the iMac from the external installation to keep using this iMac. Once you can a macOS external boot drive configured & working correctly including migrating all your files to it, then you will probably want to erase the internal drive(s) so you don't get confused with where your data is stored. I would also prevent macOS from mounting any internal drives (at least the one which is failing if a Fusion Drive setup) by using the information in the following article (you may need to change "hfs" to "apfs" in Step#8):
