No monitor display on new build after RX 480 driver install. Not detected in device manager.

Hey. Been searching these forums for answers & now looking for any advice or opinions as to my next move.

First, the specs (after upgrades):

http://uk.pcpartpicker.com/list/QcwkXH

CPU: Intel Core i5-3570K 3.4GHz (overclocked to 4.2GHz)
CPU Cooler: ARCTIC Freezer 7 Pro Rev.2
Motherboard: Asus P8Z77-V LX ATX LGA1155
Storage: Samsung 840 Pro Series 256GB 2.5" SSD
Storage: Seagate Barracuda 2TB 3.5" 7200RPM Internal Hard Drive
Video Card: Sapphire Radeon RX 480 4GB NITRO+ 4G Video Card
Case: NZXT Phantom 410 ATX Mid Tower Case
Power Supply: EVGA SuperNOVA G2 550W 80+ Gold Certified Fully-Modular ATX Power Supply
Keyboard: Corsair Vengeance K70 Wired Gaming Keyboard
Mouse: Logitech G502 Wired Optical Mouse


About 6 months ago my computer shut down unexpectedly midgame as my AMD Radeon HD 7770 stopped working. Meanwhile my EZ Cool PSU had been making some pretty awful noise, a loud whirring could be heard especially when under load. I figured this was coil whine, mainly because it had been doing this for a long time & hadn't yet packed in.

Figured it was upgrade time anyway, so bought a new case, an EVGA SuperNOVA G2 550W & a Sapphire Radeon RX 480 4GB. First I tested the EVGA PSU in my old build & it powered up fine. Curious, I slotted in the 7770 to see if it worked, it didn't. I took that out & tested the RX 480, the lights & fan came on, so I cracked on with my build.

In hindsight, I wish I had tried installing the RX 480 drivers. Also I can't remember for the life of me if I plugged the HDMI cable into the GPU or not, eager was I to make my new build.

So I took everything out of the old case & put it into a NZXT. I'd never installed a motherboard so after the usual first timer faffing around I got everything set up fine & booted it up.
I then installed the RX 480 drivers from the supplied CD, & rebooted into a blank screen. I could only get a display after removing the RX 480 from the PCI-E slot. And again, it was undetected in device manager.

Further hindsight revealed that the only drivers supplied on the CD were for Windows 10 whereas I'm using Windows 7, how I missed that I don't know. So I used DDU to remove the drivers & tried installing the right ones from online but the same troubles persist.


What I did do:-

Fresh Windows 7 install. I did this not so long ago before installing the upgraded hardware.

Resetting the BIOS by removing the motherboard battery for 10 mins.

Removed all graphics drivers in safe mode.

Changed video configuration to PCI-E in BIOS.

Powered up the computer with only the SSD, CPU & GPU connected.


What I didn't do:-

I don't think I can test the card in another computer.

I do have a spare GT 520 to test the motherboard PCI-E slot but haven't yet tried it & am almost certain the slot isn't fried anyway. That said, I've not bothered with the 7770 either.

Updated the BIOS.

Installing a Windows 10 trial.


I'm left wondering if my CPU need replacing, or am I just an unfortunate victim of having one card die on me & purchasing another which doesn't work?

Other than updating the BIOS I'm brain dead & at a loss. I must go do errands now but if anyone has any advice or obvious things that I may have missed please do let me know. Thanks.