First thing to check is that all your connections are properly seated. Sometimes one of the power cables may not be all the way in and cause issues. After you are sure you have everything properly connected check to make sure your RAM is properly seated in the slot, we have had a few instances of POST failure caused by people thinking the RAM was all the way in when it actually wasn't. Check with a flashlight from a slight angle to make sure both edges of the RAM are in the slot correctly. New slots can be quite snug.

Same again for the GPU, make sure it is fully seated in the slot. These are all things you learn as you build more PCs and cause problems even for people that have been building systems for years if overlooked. 

I looked at the sticker on the BIOS chip (the chip placed just above the PCIE1 socket); and it says "P1.49". Is that the bios version?

Yes, this is the BIOS version shipped with your board. It is unlikely that your RAM is incompatible to the point that it would cause a post failure (PC turning on but nothing displayed). It is possible but I doubt it is the cause of your issues. Far more likely is a bad connection somewhere. 

If all the steps I outlined above don't solve the issue you can try pulling the board out of the case and running it on top of the box it came in. This is called bread-boarding or bench testing. 

Let us know how it goes. 

Anything with a connector can be improperly seated. If the GPU is partially out of the slot then it can still light up and spin up if the power connectors are making contact. That does not mean the display contacts are, well, making contact. 

Double check that you have the correct 8 pin power connector hooked up to the CPU 12v, it is possible to force a PCIe 8pin connector in there so make sure that isn't the case. I have seen that cause the exact issue you are having. 

Also disconnect all your front panel leads except for your power switch. If you have something bridging the reset switch that can also cause the system to behave as you describe. It's pretty easy to hook up an LED to the reset switch header or have the reset switch stuck in a depressed position.  

Lets break this into some bullet points:

1. The 8 pin 12v CPU connector should be labeled as 12v CPU, if it isn't you can still identify it as being comprised of a 4+4 pin connector that clip together to form 1 x 8pin. It should be connected to the 4+4 pin CPU connector marked on your PSU. This is assuming the PSU you listed is correct. It should be modular (cables are separate and connect on one end to the PSU and the other to various components.)

2. Make sure they PCIe power connectors are attached to your GPU. If you don't have them connected the GPU will not output a signal. In your case it should be a single 8 pin connector. PCIe connectors are a 6+2 design so 6 pins with an extra 2 that snap together to form an 8 pin. 

3. It can take a while for a Ryzen system to post for the first time, make sure you leave the system powered on for a full 5 mins to be sure you are not turning it off again too soon. On a new Ryzen build the board will attempt to "train" the memory. This can take several tries and I have heard anywhere up to 2 minutes for the first post. Once the memory is trained, subsequent power ups will be faster.

4. Make sure all your mounting standoffs are in the correct positions and not shorting under the board.   

5. If all else fails then try clearing CMOS. You can follow the instructions in the sticky here:

http://forum.asrock.com/forum_posts.asp?TID=630&title=how-to-clear-cmos-via-battery-removal

Let us know how it goes.

So it looks like this: E = Empty slot, R = filled ram slot.

____________

|                      |

|  CPU  ERER    |

|                      |

|                      |

|                      |

|  GPU              |

|                      |

|___________|

It sucks to have issues like this on a first build, kudos for sticking it out.

So, now you need to check everything hooked up to your system, if you have a spare, swap it in. 

1. PSU

2. Monitor/TV and cables

3. Ram (you did already)

4. Peripherals (KB, Mouse etc)

If none of that gets the system up and running then it's time to pull the CPU and check for bent pins.

The components of a PC will require certain voltages (like the CPU vcore) to be exact and while the regulator circuitry on the motherboard can correct some slight variance coming from the PSU, it can't compensate beyond a certain point. 

If the PSU is new then it is fairly unlikely to be the cause, the problem is that the same can be said about all the components. PSUs are about as likely to be defective out of the box as say RAM or a GPU. Better brands and higher end models will be less likely to be faulty at purchase but it can still happen. Manufacturers can't control what happens to a component once it leaves the factory. Items can be dropped in shipping, exposed to excessive humidity etc etc.

I hope that answers your question 

So if you are taking your parts back to the store to be tested then I would bring the PSU along too. Taking parts back to the store to be checked is always a good idea when you have the option and something isn't right. If the store charges for checking parts then get them to test the CPU and motherboard first, that combo is more likely to be the issue followed by GPU then PSU. If there is not additional fee then get them all tested for your peace of mind.

Good luck GizRev, let us know what happens.

I have to clarify this for anyone reading this thread. There is a reason they are labeled PCIe and CPU 12v not just generically 8pin 12v. They have different pinouts and are even keyed differently.

Back on topic. I take it you have had no luck with any of the suggestions here? If you have not already, take it all apart completely and put it back together again carefully. Quite often that will sort things out.

For future reference, I highly recommend you do not run any system without a CPU cooler. While it should be possible with thermal throttling and other safety features it causes an extreme amount of heat, well beyond the operating heat the components were designed for. Heat like this can radically reduce the lifespan of effected components. Even just sitting the heatsink on top of the CPU without fastening it down is better than doing this.

Currently having the same posting issues with my asrock ab350 pro4.