I removed all of the DIMMs from my R820 and tried replacing them with higher capacity ones, but then realized they were not compatible with its DIMM slots. I removed the incompatible ones and put back in the original DIMMs, but now when I turn the R820 on, it says "Fatal error! No memory detected!".

I have tried all of the DIMMs in each slot, and a number of combinations recommended in the owner's manual. None of them have worked.

I'm wondering if there are any troubleshooting steps I should take, or if it is likely that I damaged some piece of hardware when changing the DIMMs.

The original DIMMs are InnoDisk ACT16GHR72W4K1600C1-VLP

The new DIMMS I tried replacing the originals with are Samsung M393A2G40DB0-CPB