Computer shutting down

  • Check to see if the policy "Shut down computer when Security Log if Full" is enabled or disabled. This policy can sometimes be overlooked as it appears to cleanly shut down the computer. To test simply clear your event logs and see if it makes an impact.
  • Viruses and worms like the Blaster worm can cause this behaviour as well.

Computer losing power, freezing, reseting under load

  • Bulging capacitors could be your problem. Faulty capacitors can be on the motherboard (most common low voltage 6.3volt high ESR switch mode ones near the processor, memory slots and AGP slot), on the graphics card, or in the power supply.
  • A faulty or underspecced power supply may only show up under high load (e.g. when a backup happens, or during peak hours). Put a volt meter on a spare drive power cable. Measure 5 volts between the red line and either black one and 12volts between the yellow one and either black one. Try swapping the power supply out regardless.
  • Check the general troubleshooting tips below.

CPU/motherboard

  • If the problem is hardware based (something just giving up the ghost) can you underclock it until replaced?
  • Can you get a slower speed processor to swap in?
  • You may have a dry joint on a flexed motherboard board that was bent into position when installed. Loosen the screws holding down the motherboard on either end (not the middle). If ther is still a problem, tighten them and loosen the middle ones. Move expansion cards to slots near mounting points, put something under the board (plastic) when pushing cards in.

Expansion cards

  • Is the VGA on-board or an early AGP card? Turn it off (for on-board), pull it out (for AGP) and put in an old PCI card (S3 or something). Run in lowest possible color/resolution. Disconnect/replace the monitor to remove the chance of back feed from a faulty monitor power supply.
  • Move the LAN card (NIC) to another slot.
  • Pull out the memory and go over the contacts with an eraser and then lightly spray/rub the contacts with INOX. Do the same for any other cards present. Is the processor an Intel Slot A P2 or P3? If so, do the same for its connector, but not if it is pinned and under a fan (i.e. Socket 7, Socket 370, Socket A, Socket 478, etc.).

Lan connections

  • Change the server to switch lan cable.
  • Check the switch QoS to that port and change the server to another switch port (may be noise).
  • Plug the server into a completely different switch (may be earthing noise).
  • Put a cheap 4 way switch between the server and the normal switch port (reduce the chance the server has to deal with NIC noise).
  • Change the lan card type.

Peripherals

  • Reseat and/or swap out the mouse and keyboard. The PS2 keyboard/mouse chip can potentially reset the machine.
  • Reseat and/or swap out the SCSI cables and the terminator. Bad tape drives cause problems on the SCSI bus and freezing problems when active or not. Pull out the tape drive and "borrow" another brand and run it externally. If not, pull out the tape, share the root directory and back it up to some other hard drive altogether. Buy an external USB/Firewire portable hard disk and run it off another box on the LAN.
  • Is the hard drive a 3.5inch Fujitsu? They stopped making them because of I/O chips that overheated. Put in a large fan to blow continuously over the drive electronics board.
  • Maxtor seem to run pretty hot as well. Early Maxtor drives use a rubber pressure connector between the board and the drive chamber to transfer power and signals into/out of it. These fail with age. If desperate, and the drive appears dead, remove the drive board and turn the connectors over. If it starts, get the data off immediately. If still desperate, find another identical drive and try it's drive board on your chamber.
  • The UPS may be faulty. Disconnect the UPS powering down alert cable (normally a serial DB9). Run the server off the UPS.

Case airflow

  • Open the case and let it run with a pedestal fan blowing onto it.
  • A case intake or exhaust fan can be a more permanent solution to this. However, be aware that it can increase the amount of dust gathering on surfaces inside the case, including heat sink fans and other vents.