Desktop hardware

PC won't POST, no display at all

No POST usually means a basic connection or component isn't making contact, and reseating the RAM and GPU fixes most cases before anything is actually broken.

Difficulty
Moderate
Time
20–60 minutes
DIY cost
$0–$0
Pro cost
$80–$200

Symptoms

  • Power light and fans turn on but nothing appears on the monitor
  • No beeps and no motherboard activity lights indicate a POST attempt
  • Monitor shows 'no signal' the entire time
  • Problem started after moving the PC, cleaning it, or installing new hardware

Likely causes

  • CommonRAM not fully seated in its slotA stick that isn't clicked in fully prevents POST on most motherboards.
  • CommonGraphics card not fully seated or power cable not connectedGPUs need to click into the slot and have all power connectors attached.
  • CommonMonitor cable connected to the motherboard's video output instead of the graphics cardIf a dedicated GPU is installed, the motherboard's own video port is usually disabled.
  • PossibleLoose or disconnected front panel/CPU power connectorA partially seated 24-pin or CPU power cable can prevent the board from powering the rest of the system.
  • PossibleFaulty RAM, GPU, or motherboardIf reseating everything doesn't help, a component itself may have failed.

What to do

  1. Power off and unplug the PC, then reseat each RAM stick fully until the clips click.
  2. Reseat the graphics card in its slot and confirm all its power cables are firmly connected.
  3. Confirm the monitor cable is plugged into the graphics card's output, not the motherboard's built-in video port.
  4. Check that the 24-pin motherboard power and 4/8-pin CPU power connectors are both fully seated.
  5. Try booting with just one RAM stick at a time in the motherboard's recommended slot to rule out a bad stick.
  6. If available, test with a different graphics card or in integrated graphics mode to isolate the GPU.
  7. Listen for beep codes during power-on, which can point to the exact failing component.

Tools and parts

  • Phillips screwdriver
  • Anti-static precaution (touch bare metal case before handling parts)

When to call a pro

If reseating components doesn't restore POST and no beep codes point to a specific part, a PC repair technician can test components individually to isolate the failure.

Safety

Generally low risk

Generally low risk for a careful person. Stop if anything looks different from what this guide describes.

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.