Question Custom built pc wont turn on/ no monitor & keyboard connection

Nov 5, 2021
Hi, I'm new to computers in general, and this is my first pc build, and I'm having trouble with the startup. Could I receive some help, please? I'm new to this site so I apologize in advance if I post in the wrong thread.
The computer turns off then back on when I press the power button, and it just repeats. The monitor has no signal when plugged into the graphics card, and I have the keyboard plugged into the back mobo IO. The keyboard is still unresponsive.
I've tried to clear the CMOS, but that did nothing. I've unplugged everything besides the PSU, CPU, and motherboard, no change at all.
  • I used one stick of ram, then turned it on. nothing. Did the other stick, and still nothing.
  • I made sure I plugged in the 8-pin CPU power connector located near the CPU socket.
  • I put in the CPU correctly, the fan as well
It doesn't have windows installed, and I can't access the BIOS because the keyboard and monitor have no connection to the pc which is turning on then off.
(I'm aware that a GT1030 will cause bottlenecking in system performance)

Motherboard: Asrock b450 Prom micro ATX
RAM: OLOy DDR4 RAM (2x8GB) @3000MHz CL16 1.35V
CPU: Ryzen 5 1600 65W
PSU: EVGA 100-BR-0500-K1-500 BR, 500W
GPU: Nvidia Geforce GT 1030 2GB
SSD: Crucial BX500 480GB 3D NAND SATA 2.5-Inch Internal SSD
Case: Cooler Master Q300L micro ATX tower


Jul 6, 2016
Usually when the computer cycles on and off like that on a loop, the motherboard is protecting the components from short circuiting or otherwise dying due to an electric surge. Few questions though to start out with, even though they may seem basic they are the first steps in figuring out the issue.

When you built the computer, did you at any point ever touch the back of the motherboard with your bare hands without grounding metal?
Is there a loose screw under the motherboard?
Did you put the motherboard risers (they lift the motherboard off of the case to prevent short circuiting) on the case?

If you haven't done any of these things, you can try by looking at the power supply. Make sure all of the connections are securely plugged in and in their correct slots. Then check the motherboards connections. Cross check with the manual to make sure everything is plugged in in the right spot. On a different note, ensure that you are using the A1 slot (closest to the CPU) for your RAM stick when troubleshooting.

At the end of all this, if nothing has worked, you could try getting a motherboard speaker and listening to the sounds it gives when it turns on, as that will tell you the issue. If that fails (no noise or no troublecode) then I'm afraid you may have to get a new motherboard through warranty. It sounds to me that the RAM slots on your motherboard may be completely dead, hence the computer being unable to POST (RAM is required for the CPU to get instructions, without it, BIOS cannot do anything). Additionally, your power supply could have came with a faulty surge protector, which could be causing the computer to constantly cycle to prevent electrical damage.
Normally turning on and off when you push the power button is memory training or a short.
Ryzen 1600 can not usually use 3200 ram on first boot so make sure the ram you have has lower speed profiles.
2133-2666 speeds are its defaults.
It can take 4-5 reboots before memory training finds latencies that work with your particular memory.