--Guides--

You may have a defective monitor or loose connection. Check your connections such as HDMI, DisplayPort, VGA, and DVI. Also check your monitor's connection to power. You may also want to try testing your monitor by connecting another device to it, and ruling it out as the problem.

Check that the switch on your power supply is on. Check it in both positions, in case it was mislabeled. Also check that the power from the wall is making it into the power supply. If the issue persists, try disconnecting and reconnecting the internal connections inside your PC if you're comfortable with that. Make sure you reinsert the cables multiple times, to break down anything that could be blocking the connection.

RAM is a common issue with PCs. Try reseating it multiple times. If that doesn't work, try using just one stick of RAM, and test each slot of your motherboard with it. If none work, try a different stick if you can, and if the issue persists after that, try to verify the RAM via another system if possible. Your RAM or your motherboard may be dead.

Your GPU (Graphics/Video Card) may be to blame for not having a video pop up on your monitor. Check the GPU's connection to power, the GPU's connection on the PCIe slot, and the GPU's video out port. If the issue persists, your GPU may have died, in which case you may have to purchase a new one or, if you can, RMA (return and replace) your current one.

A PC may crash after a file was downloaded, an .exe was opened, power flickered or surged, a cable was knocked loose, an unstable overclock caused a component to malfunction, software conflicted, or a component shut itself down to avoid melting.

Well, that depends.  If power surges or outages caused your PC to shut down, you should be able to restart it and use it as normal, but if an unstable overclock (OC) caused a crash, check the OC, and maybe mess around with voltages and clocks. 

You can hit the BIOS reset button on your motherboard or remove the CMOS battery and wait for five to ten minutes. If this doesn't work, you can try removing the battery for fifteen minutes or more.

Your expensive CPU isn't being detected by your system! The CPU may be nonfunctional due to an unstable OC, undetected due to improper seating, not receiving power, or just dead. Your BIOS software may also not support your CPU if the computer or CPU is new.

The DRAM light means that your RAM is not being recognized by your system. You can check the seating of your RAM, or an unstable OC may have also caused your RAM to malfunction. 

The VGA light is really just any display out. You can read the articles on the top of this page for troubleshooting tips.

Check your boot devices and operating system (Windows, most likely) files. You may have to set up another install if your old one has been corrupted or compromised.