[RESOLVED] [Vis-64] Stumped

I'm stumped on this one...which means the answer is probably right under my nose. :rolleyes:

I'm building a new system. Using a 790i SLI mobo with two GTX 260 graphics cards and a new Corsair "SLI-Ready" 1000w modular psu.
Each card takes two 6-pin power cables (used two 6+2 pin and two regular 6-pin). Everything is hooked up and all connections are well-seated.

Problem: The cards will not power up (fans aren't on).

Everything else powers up fine...case fans, lights, drives, etc.
At first I thought that maybe these cards just take a few moments to throttle up the fans. Nope...left it on for around 2 minutes...no fannage.

1. Tried a different power supply hooked into the mobo. Nope.
Tried switching around the 6-pin cables from the new psu. Nope.

2. Tried a different card with the new psu/mobo and used all 4 6-pin cables one at a time. It worked fine. Everything powered up. Tried all three of the PCI-e 16x slots with the different card...they all worked OK. So the problem appears not to be with the new mobo or the new psu, which led me to....

3. Tried the cards individually in a different computer. They both powered up just fine (fans came on right away BTW) and I got video on the monitor. So the cards are OK.

This mobo does NOT have an auxiliary Molex connector. The 6-pin cables provide all the power these cards need.

:confused: :confused: :confused: Frustrating......

Any ideas?

Look into the PCI-E connectors on the mobo.

Maybe dirty, corroded contacts, etc. so use pencil erasure on the card contacts.

Plug one card in and see what happens.

It's a brand new motherboard....no chance of corrosion or dirt. Like I said, I tried a different card in there and it worked fine in all three PCI-e slots. The power cables all work too, but the new cards simply will not turn on. At first I thought it might be a low power problem, but c'mon...1000w should be plenty.
I also tried with just one of the cards in there...still will not power on. This is getting real weird.

BTW...the psu is on the Nvidia SLI recommended list for certified power supplies, so it should have all the amp-rail requirements.

I remember something about that card and the 790i in MAXIMUM PC magazine about compatability and it was not good. And darn if I can find the article now.

Sorry :(

Seems a lot of folks are having fits with that chipset
http://www.google.com/search?hl=en&q...video+problems

I wish it were something simple like a chipset driver, but the dang things won't even power UP. They both power up in another computer and my 8800 GTS will power up in the new one. I'm really getting PO'ed about this one.

I do not blame you!

Well....I tried to power it all up with a brand new 700w psu and got the same results...everything lights up but the graphics cards. The mobo controls the fan, so there is a problem there. I took the 790i mobo out and replaced it with the "old" 680i...everything works...the card fans spin and I got video.
Evidently the 790i is bad...go figure. I'll be returning it to Microcenter tomorrow and exchange it for (hopefully) one that works.

This is a stupid question, I'm sure, but is an SLI bridge required to be connected to the two cards?

Yes. But that doesn't effect whether or not they power up. If you don't have the bridge in there you simply can't set it for SLI.