[SOLVED] CPU and DRAM lights on after re-installing working parts

[GarrisonP]

I'm pretty confused by this situation and would really appreciate some insight. I recently decided to upgrade my CPU and RAM to get my PC VR ready, I checked the new parts compatibility with my current build on PC part picker and aside from needing a BIOS update I was good to go. For reference, this is my current setup:

Motherboard: MSI B350m Pro-VDH
CPU: AMD Ryzen 3 1200
RAM: 2 x 4GB ADATA XPG GAMMIX D10 DDR4-3000
GPU: GTX 1060 6GB VRAM
PSU: EVGA BR 500 W

This was working perfectly as of 30 minutes ago. My new parts arrived and I set to installing them:

CPU: AMD Ryzen 5 3600
RAM: 2 x 8GB Corsair Vengeance LPX DDR4-3000

After a bit of struggling with installing the CPU cooler I turned it on only to get the CPU debug light. I realized I'd forgotten the BIOS update and re-installed the old CPU to get the update. However now my previously working CPU also gives the debug light, as well as the DRAM. I re-installed the old RAM and got the same results. I'm not sure what I could have done in this process to break my already functioning parts, but this is my first custom PC and may have messed something up. What can I do to get these parts working again?

 

[MadsModsat]

Despite the new CPU requiring a BIOS update, I have sometimes seen the failed boot attempt with the incompatible CPU make BIOS fail boot with the original CPU. It is usually easily fixed by clearing CMOS

EDIT: Sometimes it works best when clearing CMOS by disconnecting all power and removing the CMOS battery for 10 minutes, put the battery back and reconnecting everything