[SOLVED] PC turns on and off in a loop , no signal on monitor

[Rikizu]

Hello I'm new to building a PC. My computer specifications are: amd ryzeon 5 3400 as the cpu and sapphire radeon rx 550 as the gpu. I'm using a 500W power supply and connected everything in place. The problem is when I start the pc turns on and then few seconds later it turns off and back on, in a loop. I have the speaker buzzer internally connected to motherboard and there is no sound when starting up. Not sure what the issue is, I have tried new PSU and same problem occurs. Fans and everything works fine but the problem is it keeps looping on and off. ATX and 8 pin for CPU are connected so I don't see a problem with PSU. Could there be a problem with CPU, motherboard, or possibly some short circuit?

Specification:
CPU: AMD RYZEN 5 3400G 4-Core 3.7 GHz (4.2 GHz Max Boost) Socket AM4 65W YD3400C5FHBOX Desktop Processor
GPU: SAPPHIRE Radeon RX 550 DirectX 12 100414P4GL 4GB 128-Bit GDDR5 Video Card
PSU: EVGA 500 W1 100-W1-0500-KR 80+ WHITE 500W Power Supply
Motherboard: ASROCK X370 Killer SLI/ac AM4 AMD Promontory X370 SATA 6Gb/s ATX AMD
RAM: GeIL EVO POTENZA AMD 16GB (2 x 8GB) 288-Pin DDR4 SDRAM DDR4 3000 (PC4 24000) Desktop Memory Model GAPR416GB3000C16ADC
Hard Drive: Seagate - Barracuda 2TB Internal SATA Hard Drive
SSD: PNY - 120GB Internal SATA Solid State Drive

 

[R_1]

Welcome to the forums
the motherboard MAY need a software update called a flash. the OS on the motherboard is called the BIOS, the BIOS does not recognize the CPU and needs some new code to run with that CPU. once you update the BIOS or flash it, the new CPU will be supported.
that CPU is supported with Bios version P5.40. if your BIOS revision is prior to that you will need to update via the directions in the motherboard manual.
you will need a supported CPU in order to flash the BIOS.

 

[DSzymborski]

And while it doesn't help you with your BIOS problem -- you unfortunately bought a motherboard that will not work with this CPU out of the box -- I'd return the GPU while you are still in your return window. The RX 550 and the integrated graphics are essentially in the same tier, so it's a bit of a waste to pay for a GPU that does the same thing your CPU already does. You can save that money towards something that's an actual significant improvement.

 

[Rikizu]

Welcome to the forums
the motherboard MAY need a software update called a flash. the OS on the motherboard is called the BIOS, the BIOS does not recognize the CPU and needs some new code to run with that CPU. once you update the BIOS or flash it, the new CPU will be supported.
that CPU is supported with Bios version P5.40. if your BIOS revision is prior to that you will need to update via the directions in the motherboard manual.
you will need a supported CPU in order to flash the BIOS.

Thank you for your response, makes sense now! How do I update the bios via flash when I can't even log in the pc, do I need to externally update the motherboard with another CPU?

 

[R_1]

Thank you for your response, makes sense now! How do I update the bios via flash when I can't even log in the pc, do I need to externally update the motherboard with another CPU?

yes, if you need to flash the board a supported CPU will be needed to boot the board, once the board passes POST, Power On Self Test, the BIOS will launch and you can update it. once the board is updated, you can swap back to the new CPU and enjoy your system.