Problem adding a 1660 super card in existing rig

[Molock]

Hi.
I’ve got a problem and i hope you can help me :-/
First, excuse me if my english is not perfect, i’m french.

I’ve got 3 rig:
First (ETHASH NVIDIA RIG): GTX 1070 × 2· / GTX 1660 Ti × 2· / GTX 1660s × 1· / GTX 1660 × 1·/ GTX 1080 × 1
Second (ETHASH AMD RIG): RX 570 × 2·/ RX 470 × 1·/ RX 580 × 2·/ RX 590 × 2·/ RX 6700 × 1·/ Vega 56 × 1 (in reality a vega 64)
Third (ETCHASH ): RX 570 × 3

I would like to add 2 x GTX 1660 super.
I add one card with success in rig 1, BUT when i add another 1660 super in the first rig, the card does not appear or indicate “err” in red…
I tried to add it to the second rig, it’s not appear.
I add it to the last rig (only on etchash normaly, only 4GB card…) and the card shows up normally and hash correctly.

I tested the card in a computer, it works great…

I don’t understand why i can’t add this card in rig 1 or 2 ???
Power supply are ok (2000 W rig 1 and rig 2) and 850 W rig 3.
Motherboards are H110 PRO BTC+ (with 13GPUs slots)

Does anyone have an idea why it don’t work ?? :-/

[keaton_hiveon]

try other risers/cables etc.

[poneis]

Have you cleared your OCs in your rig before installing a new card? Sometimes an incompatible OC fro your last GPU is applied to the new card and it crashes immediately. You can also boot in maintenance mode to rule out this possiblity.

[Molock]

Hi. Thanks for your responses.
I’ve already tried both solutions, new risers etc…

BUT … i’ve managed 1 hour ago to find a solution…

All works great, with the gtx 1080 at the last position of the pci-e connector (position GPU 13)
I don’t know why but when i connect the gtx1080 at another position, i’m limited to 8 cards. I’ve tried also to add an AMD card from the other rig and it don’t shows up :-/
But with this **** of gtx 1080 at the last position, all works great… WTF ?_?