Question New PC boots but no bios

[Elliot98]

Hi. Built a new pc from scratch earlier. First time loading it booted up on to the bios fine. From then in it turns on providing no signal and switches off after around 5 seconds and immediately reboots.
Specs are asrock b450m(can’t remember the model
Ryzen 5 2600
16gb 2x8gb 3000mhz ddr4 ram
600 EVGA psu
I realise that I have a vega 56 which recommends more 650W but it is without the card The problem has started so I can rule that as the issue. Also had the pc on with just cpu mobo and ram in which still doesn’t work.
I’ve heard bad reviews from family and friends about asrock motherboards and wondered what anyone else thinks the issue might be?

 

[Lutfij]

Model for your EVGA psu? Are you on the latest BIOS update for your motherboard? If the system is without a discrete GPU, you're not going to see anything due to the lack of a GPU on the CPU die.

 

[Elliot98]

https://www.scan.co.uk/products/600...MIro2q9fuJ4wIV4r_tCh0yEQb5EAQYAiABEgI_D_D_BwE
That’s the psu it’s basic. As 650 is reccomeneded I see no problem why it still wouldn’t boot from gpu on a 600 no matter how bad it is. The fact it once booted up and failed to do so I find the wierdest part. The time it booted up was of the vega for reference.
I will get a 700w ASAP but I’m not certain this is the issue.