new GPU not working with new system. Pretty stumped.

Hi hope someone can help with this, because i'm somewhat stumped on how to fix it short of replacing something.

My build is as follows, an Asus H81-Plus ITX Motherboard, Intel i3 4130, Asus R9 270, 1600mhz Corsair RAM, 1tb WD Blue HDD, Silverstone 300w Plus SFX PSU, build in a Silverstone RVZ 01 ITX chassis. All components are secured and seated properly.

When assembled the system POSTs, but the 270 is not outputting video at all, a completely blank screen, i have tested every output except DisplayPort because i have nothing that uses it.. the IGP is working fine. I have ensured that the BIOS was set to use the PCIE graphics card. The fans spin, and a green light comes on when power is plugged in.

I have used an old GPU (HD4770) with the new build and it works perfectly. I have also used my new GPU (R9270) with my old computer and its displaying video just fine

I have updated the BIOS to the latest version, in an attempt to solve any incompatibility issues. Still not working.

As of now i have 3-4 possible causes. The PSU is not delivering sufficient power to the PSU, The Motherboard itself is not delivering sufficient voltage through the PCIE slot, There is some weird incompatibility with the Motherboard, or there is some issue with the riser and R9 270.

If i can solve this through a bugfix or some way that does not involve returning anything that'd be wonderful.

What power supply have you got in your old computer? At a first glance it would seem 300W is on the low side for your new build.

Okay, so i spent the evening updating the BIOS and taking the guts of my current machine and sticking them into my old chassis with a 600w PSU, and i still got the same issue.

I am now 99% sure what the actual issue IS. For some reason the motherboard isn't switching from integrated graphics to dedicated with the R9 270, something it IS doing with the HD4770. I've gone into the BIOS and ensured that it's set to PCIE graphics mode to no avail.

System is booting, posting and going into windows. If i pull the DVI cable from my dGPU and stick it into the motherboard's DVI output it displays the desktop.

Is there an issue with my board, the software, or have i missed some archaic option in the configuration. Any options or opinions?

Ok, I've just had a quick look in my BIOS (not the same board, but an Asus with UEFI BIOS) and I have the Advanced tab -> System Agent Configuration -> Graphics Configuration -> Primary Display set to "Auto" and the iGPU Multi-Monitor set to "Disabled". Can you try that?

Yeah, it's the default setting. Same result.

I'm not sure how significant this is, but in the NB PCIe Configuration panel, under the setting where you can choose between Gen1 and Gen2, it's reading x0

Have you definitely got the graphics card connected to the power supply?

Have you tried it without the riser card, I really am not sure if that card will work with a riser and I would certainly try it with out the riser card to rule that out, if it doesn't fit in your case, take it all out and place the mainboard on a box and go from there.

Believe it or not, i'm quite through. Just FYI, there is an indicator LED on the GPU that tells you if it is receiving sufficient power or not, and it has been showing green all the time.

In a previous post i mentioned that i pulled the entire system out of the RVZ01 Chassis and installed it in my old ATX chassis, along with the more powerful PSU. The system behaved in the exact same way. The chassis is also brand new, and capable of housing cards all the way up to a Titan, so i should hope that the Riser is capable of working with a midrange card such as the R9270

After eliminating as many possibilities as i could, all i can assume now is that there is some compatibility bug. I have found a build on Reddit and (sorry, can't post a link) with the exception of the PSU and Chassis is almost exactly the same as mine, yet works, the major difference being that the GPU vendor is MSI

At the moment i am waiting for Asus support to contact me.

Yes I read that, but putting it in a different case and running it out of one are very different things.

Its certainly a strange one though, I would have said riser or power personally, I hope Asus give you some more concrete info and if they do please post back here so others with the same issue might be helped :)

I have seen (and experienced!) similar issues with my media centre. In the end I had to change the video card BIOS and the EFI modules in my motherboard BIOS to get them to talk properly......it was a farce.

You might find just updating the modules in your motherboard BIOS will solve it, there is a very useful app called "UEFI BIOS Updater" (UBU) that will take your BIOS and update the modules in it for you (you then have to flash it yourself, some motherboards will require overrides as well as the BIOSes signature changes the moment it is modified)

If you are unsure of the app, let me know and I can create one for you.

Glad someone has faced the same issue as me, i've been trying to access the Asus driver download page but their site has been misbehaving for me today.

I looked into the UBI, but honestly i'm a little worried about bricking something.

At the moment it seems like the easiest option is to return something, and frankly returning the GPU seems like the most sensible option - despite nothing actually being wrong with it

Is there a BIOS switch on the graphics card? Some cards will have two BIOS versions, one for UEFI and one for legacy BIOS for compatibility reasons; switching to the latter might help.

I had a simular issue with my radeon 270x
At first i didnt had enough connectors for the card on my brand new 500W PSU(it needs 2) so i disconnected a HD and used that powercable to connect to the 2nd connector of the graphic card.. didnt work.(ofcourse because it's 5 V i think)
I found out that i needed 2 x 12 v rails ,any other powersource (for instance hd rails or any other available)not ment for GPU didnt work nor did splitting my 12 V rails into 2 rails work.
Had to buy me a new modular PSU to get it to work , it may be a stupid advice , but i was also stumped and only got it to work with a modular PSU that had multiple 12V rails