480 making me feel stupid

[Phantoms001]

I picked up a cheap 480 (150.00).  It was a store return that came back from the factory and had a full warranty. 

I have a 3 card rig that I use to test cards.  2 cards on the board and 1 riser. 

I put the 480 in the 16x slot and it works fine, mines fine, good video....

Put the 480 on a riser and the computer doesn't see it.

The reason I use this setup is that I know the riser is good.  I have 3 cards running.  Before I swap out a card, I know the board, mem, cpu, power supply (750w), ect... are all good.  I know the riser and usb cord is good because it is mining before I introduce the new card for testing. 

Anyone experience this before?  I have a good system that I know 100% works.  I remove a 290 from the riser, add the 480 and it doesn't see the 480.  Remove the 480, add a 570, it sees the card and mines fine.   Replace the 480 with a 970 and the 970 on the riser works fine.  Put the 480 back on and it won't see the card.

Is there something on the card that could be bad that won't allow it to function properly on a riser?  Works fine in a 16x slot.

Just stumped.  

 

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[MATHReX]

Did you try swapping the riser to another x1 slot in the motherboard?
Did you try another riser or another riser version?
If nothing works, well use 480 as the main GPU on the x16 slot.

[judypug1956]

Put it in the rider. Boot wait ten minutes. If it does not show power rig off.  Boot wait 15 minutes if it does not sow . Boot wait 20 minutes.  After three boots and all no shows I got no suggestions.

[Phantoms001]

Did you try swapping the riser to another x1 slot in the motherboard?
Did you try another riser or another riser version?
If nothing works, well use 480 as the main GPU on the x16 slot.

I haven't tried a different riser or version because the riser I had is a working riser. 

I'll try a different riser and different version to see if it makes a difference. 

Using it in the 16x is always a possibility, but its going to cover a 1x and I hate to run 5 instead of 6 if there is any way around it. 

[szafa]

Your 480 maybe broken.

[bileq]

which verso of 480 ? need 1 pcie power lines or 2? did you try feed with 2 pcie power lines ? did you try run your system with 1 gpu from riser card? 750w psu may not enough for 3x 480 gpu

[SodiumEx]

I've had this issue with my Rx 580 8gb. I have the blue ones and It would not work for anything. I bought a few of the white ones * Imo best looking ones , as well as it the only riser to supports every power option * and it worked flawlessly.

** Has a onboard Fuse to Protect your GPU from power surge, also has a better IC on the riser, which will keep your hashrates more stable **

White with Blue accents
https://www.ebay.com/itm/pci-e-16x-to-1x-riser-bitcoin-ethereum-btg-zcash-Newest-version-08S-white/132389754730?hash=item1ed30b576a:g:dC8AAOSwe51aANIL

White with Red accents
https://www.ebay.com/itm/VER-008S-PCI-E-1X-To-16X-Graphics-Extension-Riser-Card-4-Solid-Capacitors-15pin/152739901463?epid=3007011240&hash=item239001f017:g:mrQAAOSwKPdZ3pZH