PC won't post: cpu EZ debug light is on for 10 seconds then off

I've slowly been working my way through the list this afternoon. I will post results when I get back and finish troubleshooting.

Also to Sedivy, I haven't managed to boot into bios, let alone install windows so that is not the issue

That's what I would have thought at first, but its strange because the cpu light turns off after like 10 seconds of running

Okay, so I have finished going through the list and afterward I did some additional troubleshooting. Here's the results of each step in the list:

1 - I read the entire manual and I can't find a single thing that I have missed or done improperly

2 - This part is interesting. Yes, I had plugged in the 8 pin power connector on my motherboard. In this case, I received the same results as before. The error light comes on and turns of ten seconds later. However, I did some additional testing with this power connector. If I completely unplugged the cpu power cable, the cpu error light would stay on constantly, never turning off (meaning it did not even recognize that there was a processor, makes sense) however, I next tried only plugging in half of the 8 pins. In this case the light came on for ten seconds or so as it had been. I tried doing this with the other half and the same thing happened. This has me wondering if It is an issue with the power supply sending power to the cpu.

3 - Standoffs were installed correctly, and I pulled everything out of the case to test and the same issue happened so they are not the issue

4 - I have tried it with and without the video card and I get the same ten second cpu error light. I know it has been fully seated each time

5 - My video card doesn't need additional power

6 - I only have one 8gb stick of RAM and I have tried it in every slot. In DIMM A1 and B1 the CPU error light comes on and stays lit. In DIMM A2 and B2 the CPU error light comes on and turns off after 10 seconds

7 - I know that the RAM is seated fully. I've tried taking it out and putting it in again in various slots

8 - Owners manual says to use DIMM A2 and B2 first. I have tried all the slots. Reference 6

9 - Ryzen socket doesn't have a plastic cover on my motherboard

10 - I have reinstalled the cpu 3 separate times, each time checking to make sure it is facing the proper direction

11 - I have checked for bent pins each time I reinstalled the cpu. There are none

12 - I've reapplied thermal paste twice now and none of the times has it gone anywhere but the cap of the processor

13 - CPU fan is plugged in and spins when the computer is powered on

14 - No foreign material in any of the thermal paste used. Both stock and aftermarket (arctic silver 5)

15 - No loose screws. All the wires were behind the motherboard tray when the system was built. It is out of the case and no wires are running across it

16 - I have made sure to discharge static on the case while I work on it. I don't have a wristband though.

17 - I haven't gotten a system speaker, one didn't come with my motherboard and I haven't had the chance to go buy one yet

18 - Front power plugs were properly connected. They are no longer connected as the board is out of the case. I've been shorting the power connectors to start it

19 - Power supply is on. I feel stupid for even having to check this one, but yeah its on and I know components are receiving power because fans start and drives spin

20 - I couldn't find a list of cpu's supported by my Motherboard's bios. If someone could point me to that it would be great, although I would think my r5 1400 would be supported seeing as both it and the motherboard are newer products released around the same time.

21 - I've tried resetting the CMOS. Same ten second cpu light results

22 - I've tried both graphics card and onboard video ports. I tried both hdmi and vga ports. I don't have a dvi cable or input on my monitor

23 - All cables are tight in sockets all components are in place properly and securely

I own a digital multimeter so I checked the voltages on all of my power supply cables and everything is showing as normal.

I hope this helps. Thank you!!!!

Okay so some good news. I managed to make it into the bios with my current parts but I'm not sure how or why this worked. I currently have the motherboard out of the case sitting on its box. The RAM, CPU, cooler, and graphics card are the only things installed. No drives, etc. PSU plugged into only the motherboard. When I start the computer by shorting the power button pins, it gives me the same results I described above. However, I then shorted the pins for the reset button, I got the same cpu error light for ten seconds, but ten seconds after that the CPU fan slowed down and another 20 seconds later it posted and I am now in the bios. Not sure why this worked, but I will come back if I still need help.

No actually, mines working fine I just have to go through that power on then wait and reset process to get into bios but then there are no issues. I plugged everything in and its searching for boot devices. If yours is slowing down or freezing, make sure your CPU isn't getting too hot. If you applied thermal paste wrong or improperly installed the heatsink that will happen