Changed DIMM slots, computer won't boot

[mattdecap]

I recently put together a PC (MSI 970 gaming motherboard with AMD FX 6300 processor). Everything was running smoothly for a few days. Then I noticed that although I had 8GBs of RAM installed, my computer was only recognizing 4GB. I opened it up and saw that I had installed the DRAM in DIMM slots 2 and 4, so I switched them to 1 and 3 like the motherboard recommended. Now my computer doesn't boot at all. I tried using a single stick in all four slots, trying both sticks. I also tried returning to the configuration that was working to no avail. I tried jumping the CMOS and reseating the CPU, nothing. Any suggestions would be appreciated.

 

[mattdecap]

It turns out the sticks just weren't installed all the way. I gave them a good shove the next day and made sure I heard them click on each side and I booted up with no issue and 8GB of RAM.