New PC Troubleshooting

Fix common problems with newly-built PCs

Chances are, if you are reading this then something is not quite right with your new PC. Don't worry. It is unlikely that there is something seriously wrong.

Select from this list of possible problems and some suitable suggestions will be given.

"After I pressed the Power button..."

Nothing happened

  • Check mains plug switched on at wall
  • PSU may have its own power switch - check this is on
  • Check PSU-to-Motherboard cable(s) are correctly connected
  • Check front panel power switch is correctly connected
  • Check Reset button is not stuck 'in'
  • Check mains cable fuse

There was a loud bang (possibly with smoke) at the back of the PC Case

  • PSU was faulty or set to incorrect voltage for mains supply system. Replace PSU

PC is on but monitor shows no display and a sequence of beeps emits from the PC

  • Check fitting of CPU, RAM, Video card, sound card etc. If necessary, remove and refit these components
  • Check the motherboard manual and perform a BIOS reset procedure
  • This may indicate a faulty motherboard

PC is on but monitor shows no display and one beep emits from the PC

  • Check monitor is switched on at the wall socket
  • Check monitor power cable is connected correctly
  • Check that the monitor's signal cable is connected correctly to both the PC and Monitor
  • Check that the monitor is switched on at its front panel
  • This may indicate a faulty video card

PC is on but there are no power and/or HDD lights on the PC case front panel

  • Check correct connection of front panel connectors to the motherboard (see motherboard manual)
  • This 'may' indicate a faulty Motherboard

PC is on but HDD does not spin up

  • Check power connector to HDD is properly connected
  • Check IDE ribbon cable is correctly connected to both Motherboard and HDD
  • This may indicate a faulty Hard Drive

PC is on but CD-ROM shows no lights/will not eject tray

  • Check power connector to CD-ROM is properly connected
  • Check IDE ribbon cable is correctly connected to both Motherboard and CD-ROM
  • This may indicate a faulty CD-ROM Drive

PC is on but the CPU fan/fans do not spin

  • Disconnect the power immediately to prevent damage to the CPU from overheating
  • Check fan power cables are correctly connected to the relevant power connector (in most cases, a motherboard FAN connector or one of the PSU power connectors)
  • Disconnect the power and carefully spin the fan blades with a finger. If there is any resistance to this movement, this may indicate a faulty fan unit

On boot up, the monitor shows corrupted display

  • Check seating of CPU, RAM, Video card, sound card etc. If necessary, remove and refit these components
  • Check the motherboard manual and perform a BIOS reset procedure
  • This may indicate a faulty Motherboard or Video card

On boot up, display shows incorrect CPU type/speed

  • Check the motherboard manual for the appropriate CPU jumper settings (where applicable)
  • Check BIOS settings for CPU type (see Motherboard Manual)
  • Perform a BIOS reset procedure
  • Perform a BIOS update (with an updated BIOS, the Motherboard may support your CPU)
  • This may indicate a faulty/old motherboard

On boot up, display shows incorrect RAM total

  • Check correct seating of Memory Modules in slots
  • In cases of two or more modules, this may indicate a faulty module
  • This may indicate a faulty/old motherboard

On boot up, display shows - FDD/Keyboard/Mouse not found (or similar)

  • Check correct connection of device described, In the case of the FDD, check its ribbon and power connections
  • Check that the BIOS is configured correctly for the device described
  • This may indicate a fault with the described device or Motherboard

There was another problem not listed here?

If this troubleshooter does not solve your particular problem, follow our Troubleshooting+ article or post a message in our message forums.