Question Graphics card with PCIe cable not booting

[burnleyhome]

I upgraded my sons system from a i3 (3rd gen) to a 9th gen i3 (9100F).
Motherboard and memory were also upgraded to ASRock Phantom gaming 4 and 2x8GB DDR4 3200

Original system power supply = 450W
Original system graphics card = radeon RX480

Original system was working (3rd gen i3, Radeon RX480)

After breadboarding the new system, I got 5 beeps.
Since this i3 doesn't have onboard graphics, I retested the Radeon in the old system and it worked.
I cleared the CMOS, won't boot.

I have 2 Nvidia GeForce 750 Ti graphic cards. One that requires a PCIe plug and one that doesn't.
I tried the one that does NOT require a PCIe plug and the system booted.
Went back to the Radeon RX480 and won't boot.

I changed the power supply from 450W to 650W
Geforce 750Ti no PCIe plug = boots
Radeon RX480 with PCIe plus = no boot

I put the Geforce 750Ti with PCIe plug into the system = no boot

I put the Radeon RX480 into my other sons PC (got the GeForce 750Ti no PCIe plug from) and this booted


Summarize:
All components have worked in a PC
450W power supply
Radeon RX480 with PCIe plug= no boot
GeForce 750Ti with PCIe plug= no boot
GeForce 750Ti no PCIe plug= boots

650W power supply
Radeon RX480 with PCIe plug= no boot
GeForce 750Ti with PCIe plug= no boot
GeForce 750Ti no PCIe plug= boots

Any advice or direction for troubleshooting as my son really wants to use his old Radeon RX480 card and upgrade that for Christmas.

 

[SkyNetRising]

What motherboard exactly? There are several ASRock Phantom gaming 4 models.
What PSU models exactly? Are they modular? Did you try to use modular cables from one PSU with the other PSU?

 

[burnleyhome]

The 450W PSU is modular, the other are not modular.
The ASRock Phantom gaming 4 from NewEgg
ASRock Z390 Phantom Gaming 4 LGA 1151 (300 Series) Intel Z390 SATA 6Gb/s ATX Intel Motherboard

 

[burnleyhome]

I will get the models on the PSU's when I get home tonight.
I've built or upgraded (not including just GPU upgrades) about 10 systems in the last 20 years, but I haven't built a system in about 2 years, so I've possibly overlooked something.

 

[Vic 40]

On the bios chip of the motherboard sits a tiny sticker with the current bios,if 4.00 are you fine looking at just the bios if lower does it need a bios update before working with that cpu.

 

[burnleyhome]

Bios = 4.00
CPU is working fine. Everything boots as long as the graphics card doesn't use a PCIe plug. PSU and graphics cards with plugs work with other motherboard, CPU, memory configuration (i3 3rd gen system)

 

[Vic 40]

Tested in the second slot as well?

 

[burnleyhome]

PSU = XFX Pro650
I tried the GPU's in slot 2 (both Radeon and GeForce 750Ti with plug) and same 5 beeps.
Any more things to look at / check or shall I RMA the motherboard?

 

[Vic 40]

Can try and do that,see if mothherboard is the problem. Did you test both cables of the XFX psu?