Is it just a black screen or "NO SIGNAL" on your monitor ?
Is your GPU connected properly (All the power pins on the side?)
Is it a new setup or a failure that just came across ?
Test you GPU in different PCI-E slot.
Try to connect your monitor directly to motherboard with DVI(while slot).
Do you have a possibility to test your rig with a different GPU ?
Update - took the GPU from the store where I bought it to test. Confirmed that the GPU was dead.Good thing it's under warranty and will have another GPU in a week. Thanks!