Weird RAM upgrade issue

[scotttnz]

This week I bought a third party refurbed 2012 Mini to replace my wife's old HP Windows PC. It's an i7 2.3 and it came with 4GB RAM and a standard hard drive. I have installed a 480GB SSD, and swapped the RAM with the 2x8GB DIMMs that were in my i5 media centre Mini. (I figured I really don't need more than 4GB to stream Netflix!)

The problem is that when the 2x8GB DIMMs are installed in the new Mini I get the 3 beeps indicating a RAM error and it does not boot. If I remove the top DIMM it boots into OSX with just 8GB. If I swap the DIMMs around, I get the same symptoms, indicating a problem with the slot, rather than one of the DIMMs. But, if I install the original 2x2GB DIMMs it boots fine, and the OS recognises 4GB.

The 8GB DIMMs are nothing special. Strontium branded 8GB 1600 DD3 which meet all the specs published on the apple website. They have been working perfectly in my other mini for over a year. I swapped them back, and they still work fine in the other mini. I have also tested them in a different i7 Mini with no problems.

My wife needs an i7 and 16GB for her work, while the i5 with 4GB is more than enough for the media centre.

Any suggestions?
[doublepost=1462577440][/doublepost]If I install one of the 8GB in the lower slot, and a 2GB in the upper slot, it boots and gives me 10GB. If I swap them over it does not boot.

 

[jpietrzak8]

Edit: ignore this post, I missed the last line of the original post, which invalidates my line of thought. I can only think there's some hardware issue with the upper slot...

 

[scotttnz]

I took my testing a step further, and went and bought some Crucial Mac compatible DIMMs. They exhibit the exact same behaviour as the generic Strontium ones. I'd say that pretty conclusively proves it is a fault with the Mac. Weird that the stock DIMMs work though. Fortunately the Mac came with a warranty, so I'll follow up with the seller to get it replaced.