Hi,

I built a new PC awhile back which has been running very well (quiet and stable).
I just bumped the RAM from 8GB to 16GB - pulled the two, 4GB Patriot DIMMs PC3-1600 DIMMs out and put in two, 8GB Corsair PC3-1600 DIMMS. I did run Memtest86+ 4.20 for about 90 minutes, and it completed one pass OK. That was Wednesday.
When I got up this morning, the PC had shut itself off. It turned off twice more this morning. CPU temps looked fine, 36-37F.
Motherboard: MSI Z77A-G43
CPU: Intel i5-3570K, no overclock.
PSU: Seasonic S12 500w
I'm thinking it's the memory. When I went to run Memtest86+ again this morning, the PC shut off after 2-3 minutes.
Any other thoughts?

Please help.

I didn't find the right solution from the Internet.

References:-
https://arstechnica.com/civis/viewtopic.php?f=8&t=1218665
Business Analytics Video

Thanks!