ASRock A520M Gaming - not booting to bios

I have built a new PC on the A520M Phantom Gaming 4 motherboard, and it won't boot into bios - absolutely no dsiplay at all.
Not yet loaded windows as cannot get that far.
I switch on, press power button and lights come on, fans run but that is all.
I have no additional boards installed, and even removed the USB connections.
I have tried both HDMI and DP video out.
Items installed are -

• A520M Phantom Gaming 4 motherboard
• 500W GameMax RPG Rampage 80 Plus Bronze PSU
• Kingston FURY Beast 32GB (2x16GB) 3200MT/s DDR4 Memory Kit (with both and one stick (slot A2 & B2 - or only B2 or B1)
• AMD Ryzen 5 5500 6 Core/12 Thread AM4 CPU

I have tried removing the CMOS battery and replacing. I've checked all voltages from power unit and all are correct, so I don't think its a voltage issue.
Must be either M/B, cpu or ram. I suspect m/b.
I have suscessfullt previously built a few PCs (one last week using B550 Phantom Gaming4 MB) without problems. Please point me where I am going wrong.
Peter

I also forgot to say that I had a EVGA Geforce GTX970 installed originally then removed it to ensure it wasn't that causing problem- still no video. Despite the fact it had come straight out of a working pc the day before.

An update for further information....

I am building two PC for my two grandsons - one already built and working and this one.

So I have just tried swapping the graphics card from the working one to this.
ASUS GeForce RTX 4060 Dual Evo OC 8GB GDDR6

But it still isn't working so that lets out the graphics side of the problems.

{and yes after putting it back, it works ok in the original pc}

I truely am baffled!

I have since found and connected a speaker.
I have swapped all except the CPU and get 3 beeps (with original and swapped components).

I tried swapping the CPU.

There is still no display but the three bleeps now rapid sort of bleep-bleep-bleep.
Previously it was bleeeep ----- bleeeep ---- bleeeep, long beeps and not as rapid.
If you understand my meaning.

I didn't appreciate there was a difference until now.

Hey @pads - welcome to CF

This certainly does sound to be a bit of an odd issue. My first thought would be to suggest trying to reseat the CPU, RAM etc if you haven't already done so.

Other than that - does the motherboard have any LEDs? If you switch it on and any of them stay on - which ones? They can be pretty hard to read the silkscreen so might be helpful to refer to the motherboard manual (if there is one supplied... usually you have to go online now!) as if any remain on it will point you towards the fault.

A bit of further research leads me to the beep codes for your board - 3 short indicates it could be a RAM issue. Considering you've already tried running off a single stick, it might be worth nicking some compatible RAM from another machine to rule out having a faulty set of RAM.

Overall though, my gut feeling sadly is you've got a dodgy motherboard and you'll have to go through the returns process for this one.

I've been building computers for many year (since 1979 -UK101 - look it up) and this is the worst set of problems I have ever had.
Turns out that the monitir has a dodgy DP input (I'm using my own 2nd monitor) HDMI is fine.
So got up windows. However - big however.

1) To update to win11, I need secure boot. I go through the process described by ASRock - ASRock > FAQ
2) But then the system just continually boots to BIOS. and the boot priority list has disappeared.

The only way I can get it to boot to windows is to clear/rest bios, but then I am back to step 1 !!

Nightmare!! Glad you got it booting at least - good sign. Wouldn't have put it down to the DP port but stranger things have happened - perhaps the monitor is sending some dodgy voltage back to the board and it's detecting this and throwing a wobble.

Secure boot is indeed a pain in the rear... is there currently a Windows system already on the disk or are you installing from scratch?

Also try this routine > follow the ASRock instructions up till step 2. Instead of choosing secure boot mode custom, try standard.
Then, CLEAR the 'Secure Boot Keys' on the next step.
Enable secure boot, save settings and reboot.

There's currently windows10 on the disc - with programs and data !
I'll try your suggestion.
I'm currently cloning the disc - just in case

That might be the showstopper to booting -- the secure keys are set up during the Windows install, so if you transplant a drive from another system you might not have much luck getting it booted. Fresh install of 11 should -hopefully- do the trick - if you want to transfer data from an older system, install 11 to a new drive then plug the old drive in once installed to copy stuff across

All sorted
1 Not only did I have problems changing discs to GPT (more than 3 partitions)
2 Then win11 wanted to reright everything because the languages didn't match.
3 Tried all sorts of suggested ways - eventually resorted to tweeking the registry!

ANyway thanks for the guidance along the way.
Peter