How to Troubleshoot a Computer with a Black Screen and Blinking Cursor

You’re familiar with the various images displayed on the monitor as your computer boots, so a pitch black screen with a lone blinking cursor is cause for closer examination. This screen typically appears when your computer cannot boot properly, and its power-on self-test (POST) failed.
Essentially, as the computer checked its installed hardware and ran the BIOS, it encountered a problem that prevented proper start-up. A blinking cursor is never a good sign, but it doesn’t always mean a death sentence for your computer. In some cases a restart can correct the issue, while other times it requires a little more troubleshooting.

Perform a Hard Reset

As your PC runs, it stores information in the temporary memory to help programs run faster and more efficiently. Sometimes this stored data can interfere with proper booting if the computer doesn’t clear it out during shutdown. Reset your computer to clear the memory and reestablish the proper connections between the BIOS and installed hardware. Disconnect any connected peripheral devices, such as a printer or scanner, and power down the computer. Unplug the power cord from the wall and disconnect it from the back of the computer. Press the power button and hold for 30 seconds to discharge any residual electricity in the power supply’s capacitors and reset the machine. Reconnect the power cord, plug in to the outlet and attempt to boot. If it boots successfully, reconnect your other devices one at a time and update their drivers.

Check Installed Hardware

One reason your machine may fail during boot is a problem with an installed component, specifically your RAM or hard drive. Shut down your computer and open the case. Check the various cables and connections to and from all installed components to make sure everything is securely connected and seated properly. Use canned air to clean any built-up dust or lint that may be preventing proper connections. Visually inspect all components to check for signs of damage, such as burn marks or cracks. If any component is loose or damaged, it will not communicate with the rest of the computer properly and prevent proper boot. A damaged fan can prevent proper venting, which can promote overheating inside the case and cause operational issues. Make sure your fan is working properly, with no broken blades, and keep the vents clean and clear for maximum airflow and cooling.

Reset BIOS

Your computer’s BIOS starts when you boot, and ensures all hardware is working properly before handing start-up procedures over to the hard drive and operating system. If the BIOS isn’t configured properly, your computer won’t boot properly. Windows 8 users can enter the BIOS settings by restarting and selecting “Troubleshoot Refresh or Restart Your PC or Use Advanced Tools” from the Choose an Option screen. Under Advanced Options, select “UEFI Firmware Settings” and then “Restart.” The computer will reboot and open the BIOS settings. A word of warning — you need to know what you’re doing when dealing with BIOS settings, as one false move could render your computer completely non-functional. Seek the help of a knowledgeable tech before making any changes to your BIOS.

Failed Hard Drive

If all installed components are functioning normally and fastened securely, and restarting returns the same blinking cursor result, the unfortunate truth is your hard drive may have failed. Your computer’s hard drive contains all the files and data for your operating system, and if this important piece of hardware goes belly up, so does your ability to use your machine. You can install a new hard drive into your desktop to resurrect your system, but you’ll have to re-install your operating system and all programs.