Computer with Intel® Pentium® Processor Does Not Boot, Has Lights or Fans, But Nothing on the Monitor Screen

Last Reviewed: 26-Jul-2017
Article ID: 000007092

Important note: Only a computer professional should perform assembling, disassembling, upgrading and troubleshooting computers since the electronic devices may cause serious damage to the installer, the system, or its components if it is done improperly. Before attempting to disassemble or assemble computers, install components in a computer or troubleshoot computers, carefully review the documentation specific for the computer and its related components. Lastly, make sure to follow Electrostatic Discharge (ESD) procedures.

  • Determine if the system worked before. Determine if there have been any recent changes. Often if a recent change is been made, the recent change is the cause of the problem.
  • Make sure that the monitor is plugged in and that the monitor is on.
  • Make sure that the video cable is connected properly at the monitor and the PC.
  • Determine if there is power light on the monitor. Most monitors will have a green light indicating it has sufficient power and is getting a video signal and an amber light if it has power but it is not getting a video signal from the computer. If you have no lights, it is most likely a problem with the monitor. Make sure that the monitor is connected to a working AC outlet, the AC power cord is plugged into the wall outlet and the monitor. If you have any on/off switches for the outlet, make sure that the switches are on. If the problem still persists, try replacing the monitor and try the monitor on another AC outlet and another system. If you have an amber light, it is most likely a problem with the computer.
  • Check the brightness and contrast controls on the monitor. The monitor might be dimmed where you cannot see anything on the monitor.
  • If you have a light on the monitor, use a voltmeter or an AC wall outlet tester found in a hardware store to confirm that there is adequate AC voltage at the wall outlet for the computer.
  • If your AC outlet for your computer is connected to an on/off outlet switch, make sure that it is on.
  • Ensure the selected motherboard is appropriate for the processor model, frequency, and stepping you are planning to use.

    For more information:
  • Verify that your chassis/case and power supply is appropriate for the processor model and frequency and the motherboard you are planning to use. For Intel Pentium 4 processor based systems, you should be using an AXT12V, SFX12V or PS3-12V power supply.

    For more information on chassis:
    For more information on power supplies:
  • Verify that the power supply has the capacity to power all the devices used in your system. It is recommended to use at least a 200 W power supply, but may require a power supply with a higher capacity depending on the number of devices and the type of devices connected to your computer.
  • Make sure the power cables inside the computer are attached correctly and secure. You will need to attach the main power connector and a 2x2 power connector. In addition, some motherboards may require a 1x6 optional power connector.
  • Make sure the drive ribbon cables inside the computer are attached correctly and secure. Be sure to check the orientation of pin 1 of Hard Drive. If the ribbon cable is connected backwards may cause the computer not to power up.
  • Check for foreign objects such as screws that may ground the motherboard and make sure the screws that hold the motherboard are not too tight.
  • Check the cables that connect from the case to the motherboard. Be sure to include the power switch (PWR SW) and power LED (PWR LED). Refer to the motherboard manual for more information.
  • Use a voltmeter to verify that each output from the power supply is correct. If any output is very low (especially the +5 volt output, replace the power supply).
  • Use a voltmeter to verify the PowerGood signal is +5 volts. If the signal is below 1.0 volts, there may be a short or overload causing a constant reset. Consider replacing the power supply.
  • Check for shorts and overloads inside computer by removing nonessential items such as extra controller cards and IDE/ATAPI devices and turning the computer on to see if it starts to boot. Leave the motherboard, power supply, RAM or processor. If the problem goes away, there was a short or overload with one of the components that you just removed or one of those components is faulty. Replace each of those one at a time until you isolate which is causing the problem. If the problem still occurs after removing the nonessential components, the problem has to be with the motherboard, power supply, RAM or processor.
  • Remove the processor and RAM and reinstall them to make sure that they are installed correctly.
  • Make sure that you have mounted the motherboard correctly with the spacers/stand-offs. In addition, make sure that when you insert the screws to tighten the motherboard into place, make sure not to tighten the screws too much. Lastly, for the Intel Pentium 4 processor - 423 pins, make sure that you are using the four metal stand offs located underneath the processor. For the Pentium 4 processor - 478 pins, make sure that you are not using the four metal stands located underneath the processor.
  • Determine if motherboard/system has any security features, which would disable boot.
  • If you are using RDRAM, make sure that all memory sockets of a channel are filled with either a memory chip or a continuity module. In addition, if the motherboard has multiple channels, make sure that you fill the first channel once and that you check to see which memory sockets go with each channel. Lastly, the RDRAM often has to be installed in pairs of the same type of memory chips. For example, you would have to install two sticks of 64 MB of RDRAM running at 800 MHz.
  • If you are using SDRAM or DDR-SDRAM, some motherboards require you to populate the memory sockets starting with the first socket. Refer to your motherboard documentation for more information.
  • If the problem still persists, swap the RAM with known good RAM. In addition, test the suspected RAM in another known working system.
  • If the problem still persists, swap the processor with a known good processor. In addition, test the suspected processor in another known working system.
  • If the problem still persists, swap the motherboard with a known good motherboard. In addition, test the suspected motherboard in another known working system.
For more information about troubleshooting IA platform systems, refer to the Troubleshooting for the IA Platform PDF document.