How to Diagnose Motherboard or Processor ProblemsThe motherboard and processor are two of the most important hardware components inside the computer. The various pieces of hardware inside the PC communicate with one another through the circuits on the motherboard, while the CPU stores and executes programming instructions. The motherboard and CPU can both be expensive to replace, however, but diagnosing hardware failure on your own can reduce the potential repair costs for your business. Diagnosing a defective motherboard or CPU isn't an exact science, however, as most hardware components exhibit similar symptoms when failing.Step 1Turn off the computer. Disconnect the power cable from the back of the PC. Unscrew and remove the cover from the case.Step 2Touch a bare metal surface, such as the computer chassis, to ground yourself.Related Reading: How to Diagnose Computer Problems With CPU Usage in System ExplorerStep 3Reconnect the power cable and then turn on the computer. Listen to the internal speaker for a sequence of beeps (call beep codes) that the motherboard produces when the system detects a problem with a critical hardware component.Step 4Open a browser and navigate to the motherboard manufacturer's website. Look up the motherboard model and review the documentation for the component to find out which device is responsible for the beep code, if applicable. Confirm that the device is properly installed to the motherboard. If reseating the hardware fails to fix the problem, you might need to replace the component.Step 5Power off the computer if the PC fails to emit a beep code. Disconnect the power cable and all peripheral components connected to the rear of the PC.Step 6Uninstall all hardware from the computer except for the motherboard, CPU, power supply, hard drive and video card.Step 7Loosen and remove the brackets securing the heat sink and processor fan to the CPU. Twist the heat sink back and forth to weaken the seal binding the component to the top of the processor.Step 8Extract the heat sink from the PC. Put a finger on the processor. If the component is too hot to touch for longer than a couple seconds, the CPU might be overheating. Upgrading the heat sink assembly will improve cooling and stop sudden system shutdowns.Step 9Release the bar securing the CPU to the motherboard. Lift the CPU out of the computer and check the surface of the component for bent or broken pins, which indicate that the hardware should be replaced.Step 10Line up the triangle on the edge of the processor with the triangle on the processor slot. Place the CPU on top of the slot and then push down the bar to lock the component in place.Step 11Reconnect the power cable and press the power button. Check the power indicator light and listen for the spinning of the system fan. If the indicator light remains off and the system fan fails to power up, the power supply unit might be defective. Replace the PSU; if the computer still fails to power on, the motherboard might be at fault.Step 12Shine a flashlight on the motherboard and check for broken onboard chips, damaged capacitors (which look similar to an AA battery), burnt traces (the lines traveling along the surface of the board), or cracks or fractures in the board itself. If the motherboard has incurred physical damage, it must be replaced.Step 13Turn off the computer. Locate a jumper labeled "CLRTC" or similar. Use a pair of tweezers to remove the shunt from the first two pins. Place the shunt on pins two and three, wait 10 seconds, and then return the jumper to its original configuration.Step 14Reconnect the keyboard to the computer and then restart the PC. Follow the instructions on the boot screen to go to setup.Step 15Press the button as shown on the main menu to load fail-safe defaults or use the directional pad to select the appropriate option and then press "Enter."Step 16Press "F10" or go to "Save and Exit" and then press "Enter" to restart the computer. If the computer still fails to boot properly, or if the same issues occur after loading the operating system, the motherboard or CPU might need to be replaced.