RX 580 doesn`t boot

Hello ,

I assembled the following configuration today :

Motherboard   - Asrock x370pro4
CPU  Ryzen 1700
Ram Corsaid Hyperx 2666 2x8g
PSU Fortron Hydro 700w
GPU AMD RX580 8gb (power color )
SSD Adata sx8200 480 
Windows 10 freshly installed 

Test materials 
nvidia gt 710 2gb
4 gb 2400 mhz ram (can`t remember the name)

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The issue i`m having is the following : 

When I plug in the RX580 , i get 5 short beepcodes and i get no display . Note I believe the windows boots (i will explain bellow ) Note : The fans of the AM RX580 spin ,but no signal . All test were done outside the case on insulated surfacer I have no acceess to spare PSU .

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What i`ve done 
1: Checked voltages of PSU with multimeter - all are corerect
2: moved ram sticks to all slots and tried only 1 ram - no effect

3: Used different gpu and ram  - the motherboard booted 
4: Updated bios to 5.x
5: removed test ram and place my own  - the computer booted (with both sticks as well)
- tested the RX580 like that - no effect
6: installed windows with nvidia gpu - everything installed correctly 
7: loaded the amd video drivers that came with the motherboard - still no luck with RX580
8: Messed around in the bios - changed to UEFI only , Force PCIEgen 3 speeds, basiclaly anything that had UEFI and PCIE that I could see 
- reinstalled windows with UEFI only selected and with CRM disabled . no luck
9: Restored all bios to defaults except for UEFI

10: Removed SSD and placed nvidia card in the second PCIE slot - the bios booted
11: Attempted to dual-boot with nvidia in second PCIE and AMD rx580 in first PCIE - -Bios Booted .

*Note :::: Checked the bios to see if detects the AMD, but there was nothing 

12: Did stress test with aida64 , while the nvidia gpu was installed -voltages of the PSU were spot on .

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Might have missed something but yeaa ...

So Basically my Questions :

1: Do you think the RX580 is defective ?
2: Is there something I need to configure so that the GPU boots ?

Make sure the graphics card is pushed all the way into the slot and is secured. Also make sure that the power cable is plugged into the graphics card

Edited by eminem87 - 03 Nov 2018 at 7:41pm