Mining Troubles

[mechtronic2001]

I have 4 cards on the mobo(3x290s and a reference HD5850) and my machine suddenly stopped working. Whenever I start to mine the screen goes black and I have to reboot to get the screen back. I thought my riser cables were an issue. I removed the primary and tried again with the same results.  I have now connected all cards directly to the mobo and got the same results again. I changed the .conf and finally got the 3x290s(the only cards that will fit directly to the mobo) to run, but only with the settings set way lower than I originally had. I am no longer able to overclock and the intensity is only set to 16 instead of 20. The cards are only achieving between 200-250khs each now. Is it possible that there is a mobo issue? maybe with the pci-e lanes or something? That's what I am leaning towards, but I'm not sure if it could be a psu issue or something else entirely. I'll include specs below if that helps.

MSI 890fxa-gd70
Sempron 145
8GB Ram
300GB velociraptor
3xR9 290(2 msi, 1 sapphire)
windows 7 64-bit

Anyone that's had a similar issue please jump in. Anyone with suggestions would be much appreciated, thx!

[backtrackit]

If it was me I'd try the cards one by one, if all work like normal on their own then I would suspect the PSU/s. Which PSU's do you have?

[mechtronic2001]

If it was me I'd try the cards one by one, if all work like normal on their own then I would suspect the PSU/s. Which PSU's do you have?

I did go ahead and test individually with cards, using different pci-e ports, with/without risers, etc.

My PSU's are here:
http://www.newegg.com/Product/Product.aspx?Item=N82E16817190033

http://www.newegg.com/Product/Product.aspx?Item=N82E16817182188


The rosewill is the primary so it runs the system, hdd, and 1 card

the xion runs 2 cards

I don't think the psu's are being pushed to hards, but that doesn't mean they could be bad i guess. Total wattage with the 3 cards was around 1300 watts.

edit

I went ahead and ordered a new mobo so we'll see how that goes.