Desktop hardware

Motherboard shorting from incorrect standoffs

A motherboard that won't power on right after a build, with no obvious cause, sometimes has a hidden standoff in the wrong spot causing a short against the case.

Difficulty
Moderate
Time
30–60 minutes
DIY cost
$0–$0
Pro cost
$100–$200

Symptoms

  • New build won't power on at all despite everything appearing connected correctly
  • Momentary spark, smell, or a stubborn refusal to power on right after installing the motherboard
  • No signs of life whatsoever, not even a standby light
  • Problem is specific to this case, and the board tested fine outside it (if tested)

Likely causes

  • CommonA case standoff installed in a position without a corresponding motherboard mounting holeThis lets a screw or the board's underside touch the standoff and short the board's circuitry against the case.
  • PossibleMissing standoff causing the board to flex and touch the case directlyUneven support can let part of the board's underside contact the case.
  • PossibleA stray screw or metal debris resting on the motherboardSmall metal debris from installation can bridge components unintentionally.

What to do

  1. Power off and fully unplug the PC before opening the case.
  2. Remove the motherboard and carefully check the case for any standoffs installed in positions without a matching motherboard mounting hole.
  3. Remove any extra or misplaced standoffs, keeping only the ones that align with actual mounting holes on your specific motherboard.
  4. Inspect the case interior for any stray screws or metal shavings that could be resting against the board.
  5. Reinstall the motherboard onto only the correct standoffs, using a case standoff tool or nut driver for a secure but not overtightened fit.
  6. Reconnect everything and attempt to power on again to confirm the short has been resolved.

Tools and parts

  • Nut driver or standoff tool
  • Flashlight

When to call a pro

If a board still won't power on after correcting standoffs and checking for debris, have it tested by a professional to rule out damage from the earlier short.

Safety

Use caution

Always fully unplug the PC before working inside the case, since a short circuit situation means components may be carrying unexpected current paths.

Related guides

Operator provides AI-generated troubleshooting information. It can be wrong. For safety-critical, electrical, gas, structural, medical, automotive safety, or other high-risk problems, consult a qualified professional.