Hi, and welcome to JustAnswer! My name is XXXXX XXXXX I am excited to get started with you.So I can better assist you, I will need additional information. So far, it does sound hard ware related but there are some steps we can take to isolate your issue further. If you still have the original hard drive, what happens when you install it?
The application that allows you to view your crash log is called console. Just click on the magnifying glass in the upper right corner and type in console.
When it shuts off again, try to reset your PRAM
In the left column, click on System Diagnostic reports Is there anything listed
Can you make out what it says?
if you click on the arrow next to The diagnostic report, it should show you the application
Next, click on /Library/Logs and click on Crash Reporter. Is there anything listed there?
That does not sounds like that is the issue.
click on /Library/Logs and click on Crash Reporter. Is there anything listed there?
Ok you can close console. Console will not record hard ware failures. If nothing is showing up pertaining to your constant restarts we can start looking at Resetting your PRAM first and then I will advise you to insert your old Hard drive
1.Shut down the computer.
2.Locate the following keys on the keyboard: Command (⌘), Option, P, and R. You will need to hold these keys down simultaneously in step 4.
3.Turn on the computer.
4.Press and hold the Command-Option-P-R keys. You must press this key combination before the gray screen appears. Let computer chime 4 times
5.Hold the keys down until the computer restarts and you hear the startup sound four time.s
6.Release the keys.
Log in and let your computer sit to see if it will shut off. How long does it normally take to shut off?
Disk utility will only tell you if there is something wrong with the hard drive
You can run a quick scan to see if the drive is ok
I defiantly do not think it is the hard drive. You may have even accidentally shocked the logic board while replacing the hard drive if you were not grounded wearing ESD protective wear. ( Small chance but does happen) Since you only had it a week, my suggestion is to place the old HD back into the computer and exchange the machine where you purchased it
No problem. Best of luck. Was there anything els I can assist you with?