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I am working on a family member’s computer and recently updated it to Sierra and upgraded by swapping two 2 GB RAM modules for 4 GB modules (4 GB up to 12 GB total). The plan is also to upgrade the HD or swap the CD drive for an SSD to make a Fusion drive. However, after the upgrade, I’ve been having shutdowns of the machine. It boots fine and loads Sierra. Then it will load a webpage or two and then shutdown. It has also shutdown when trying to copy files to it. I tried to copy the details of the error log, but the computer shut down after copying them and before I could post them. Any ideas? Is it something with the HD and I should just swap it out? Is it something more fundamental like the motherboard? Any input is greatly appreciated.
How about pulling the new RAM and just running the system with the original 4 GB is the system stable? If the system is stable the memory you bought needs to be checked. If the system is still shutting down then there is a deeper problem. I don’t see moving forward here with the upgrading of the HD or adding a SSD until you solve the stability issue. See if you can run the built-in diagnostics. Does an error message pop up? Is the system shutting down while running diagnostics? If you suspect the drive is failing see if you can connect this system to a second Mac using Target Disk Mode. If you can connect it up you can use the other Mac to diagnose the drive using Disk Utility. Let us know what you find out then we can move forward on how to fix and what hardware you’ll need for the HD upgrade or adding the SSD. References: Startup key combinations for MacShare files between two computers with target disk mode
Peterson sorry man make sure your hard disc is tightly positioned,some times it may be checking. secondly your RAM should be not less than 2GB,insurficient space causes such related problems. lastly if it persists change the windows,,,,,thanx