Cleared CMOS annd tried the other PCIe slot...no dice.
1. Does the old card work in the same system?
2. Have you tried using different PCIe inputs on the PSU - with different cables? Do you have the 6/8-pin connectors snugly secured in the new videocard? Did the card snap into the PCIe slot?
3. Was the new card you received in a brand new/sealed box?
4. Have you tried
both of the DVI ports on the R9 290? Are you using any VGA adapter to connect to your monitor? Only one of those ports seems to be able to run digital monitors, the other is analog:
Max Supported Resolution (ANALOG) : 2048 x 1536
Max Supported Resolution (DIGITAL) : 2560 x 1600(DVI);4096 x 2160(HDMI;DP)
http://xfxforce.com/en-us/products/...9-290-double-dissipation-edition-r9-290a-edfd
5. Have you tried flipping the BIOS switch on the GPU between 1-2 to see if there is any difference?
6. Try uninstalling the AMD drivers completely while the old card is in the system and just boot. While at it, might save your OCed profile/settings and load Optimized/Defaults in the BIOS and try booting that way.
7. Try only leaving the only SSD/HDD with the primary OS connected, while disconnecting all the other SATA devices upon boot. When you shut down the computer, make sure to use the power off switch on the back of the PSU and wait at least a minute before restarting.