Are you using a FRESH copy of Windows OS ? What about GPU drivers ? Tried a clean re-install ? Tried using a different Monitor cable as well ? When does the screen go black, during desktop/browsing idle mode, or while gaming and/or watching/streaming videos ?
Anyways, first off, kindly provide full PC specs, including the PSU's model number.
Complete system specs should ALWAYS be accompanied with any driver, hardware, or performance question. Do not post DXDiag reports as they contain a TON of useless information. Posting a DxDiag in place of a System Spec list tends to ward off potential members from helping you.
Please supply the following system details/information. No need to provide each and every detail though, only relevant to your issue at hand. This is just for reference:
(Complete System Specs)
-CPU make and model# (clock speed/voltage, type of cooler, and "Core" temperature @ idle and load)
-Motherboard make & model# (include Bios version if graphics card is not recognized or you are having stability issues)
-RAM (amount, clock speed, model#/link of kit, configuration)
-Graphics card(s) make and model# (clock speed, voltage if modified, Driver version and GPU temp both @ idle and load)
-Power supply make,model#, "AND" age (note if using 110V or 220V A/C input)
-HDD/SSD configuration (ie: Raid setup/ back up/ OS drive/etc..)
-Case/Chasis make,model# (fan make, model#, and configuration if having thermal issues)
-Operating System (If using Windows note Framework and service pack version)
-Monitor make, model#, and resolution (If model# is unknown list resolution and refresh rate)
*If the unit is a "laptop" or "All-in-one" system you must note the make and model# of the unit. Be sure you are ALWAYS using the OEM/manufacturer's driver updates for the unit.
-Note the nature of the "crash" in detail, as there are several definitions for the word "crash".
*If "performance" related issue:
-Note the "exact" point in which the performance reduction occurred (ie: After Windows update, After Bios update, After Driver update, After thermal system shutdown, After Hardware change/upgrade etc...)
*For diagnostic purposes please disable the following:
-Any/all Antivirus/ Anti-malware software