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Computer Won't Turn On? How to Fix a Dead PC or Laptop

4 min read •
Beginner Computer Boot Power Fix

You press the power button and nothing happens. Or the lights come on but the screen stays black. Or it starts to boot then shuts off. Each symptom points to a different problem.

Symptom 1: Absolutely Nothing Happens

No lights, no fans, no sounds. Completely dead.

Desktop

  1. Check the power cable — unplug and replug both ends (wall and PC)
  2. Try a different outlet — plug a lamp into the same outlet to confirm it has power
  3. Check the PSU switch — the power supply has a switch on the back (I/O). Make sure it is ON (I)
  4. Try a different power cable — use one from a monitor or other device
  5. Hold the power button for 30 seconds with the cable unplugged — this drains residual power. Plug back in and try
  6. Open the case and check connections — the 24-pin motherboard power cable and 4/8-pin CPU power cable might be loose

If none of these work, the power supply is likely dead ($40-80 replacement).

Laptop

  1. Plug in the charger — battery might be completely dead. Wait 15 minutes then try
  2. Try a different charger — chargers fail. Borrow one or test with a known working charger
  3. Check the charging light — if the LED near the charging port does not light up, the charger or port is bad
  4. Hard reset — unplug charger → hold power button for 30 seconds → plug charger in → try power button
  5. Remove the battery (if removable) → plug in charger → try power button. If it works, the battery is dead

Symptom 2: Lights and Fans On, But No Display

The computer seems to power on (fans spin, LEDs light up) but the screen stays black.

Check the Monitor

  1. Is the monitor on? Press its power button
  2. Correct input selected? Press the Input/Source button on the monitor — switch between HDMI, DisplayPort, etc.
  3. Cable connected? Unplug and replug the display cable firmly on both ends
  4. Try a different cable — HDMI cables fail
  5. Try a different monitor/TV — rule out a dead monitor

Check the PC

  1. Listen for beeps — beep codes tell you what is wrong (see below)
  2. Reseat the RAM — open the case, remove RAM sticks, put them back firmly until they click
  3. Try one RAM stick — if you have two, try each one alone in different slots
  4. Reseat the GPU — remove the graphics card and reseat it. Or try the motherboard's built-in video output (if available)
  5. Reset CMOS — remove the small coin battery on the motherboard, wait 1 minute, put it back. This resets BIOS settings

Laptop Black Screen

  1. Brightness key — press the brightness up key (usually Fn + F5 or similar)
  2. External monitor — connect to a TV/monitor via HDMI. If external works, the laptop screen or cable is bad
  3. Hard reset — hold power 30 seconds with charger unplugged and battery removed (if possible)

Symptom 3: Turns On Then Shuts Off

Powers on for a few seconds then dies. May repeat in a loop.

Most common causes:

  1. Overheating — dust clogged the heatsink/fans. Open the case and clean with compressed air
  2. Bad RAM — reseat or replace RAM sticks
  3. PSU failing — power supply cannot sustain load. Replace it
  4. Short circuit — a loose screw or cable touching the motherboard. Check for anything metal touching the board
  5. CPU overheating — thermal paste dried out. Reapply thermal paste (requires removing the CPU cooler)

Symptom 4: Boots to BIOS But Not Windows

You see the manufacturer logo or BIOS screen but Windows never loads.

  1. Boot order — enter BIOS (press Del, F2, or F12 at startup) → check boot order → make sure your hard drive/SSD is first
  2. Loose drive cable — open case and check SATA or NVMe connection
  3. Windows boot repair — boot from a Windows USB installer → "Repair your computer" → Startup Repair
  4. Safe Mode — press F8 or hold Shift while clicking Restart → Safe Mode → uninstall recent updates/drivers

Symptom 5: Blue Screen (BSOD)

Windows shows a blue screen with an error code and restarts.

Common BSOD fixes:

  1. Boot into Safe Mode — uninstall recently installed drivers or programs
  2. Run memory test — Windows Memory Diagnostic (search in Start menu)
  3. Check disk — open Command Prompt as admin → chkdsk /f /r C:
  4. Update drivers — especially GPU and chipset drivers
  5. Check for overheating — clean dust, check fans

Common BSOD codes:

Code Likely Cause
CRITICAL_PROCESS_DIED Corrupted system files
KERNEL_DATA_INPAGE_ERROR Failing hard drive
IRQL_NOT_LESS_OR_EQUAL Bad driver or RAM
WHEA_UNCORRECTABLE_ERROR Hardware failure (CPU/RAM)
PAGE_FAULT_IN_NONPAGED_AREA Bad RAM or driver

Beep Codes

If your PC beeps during startup, count the beeps:

Beeps Meaning (AMI BIOS)
1 short Normal boot (good)
1 long, 2 short Video/GPU error
1 long, 3 short Video/GPU error
3 short RAM error
5 short CPU error
Continuous RAM or power issue

Beep codes vary by BIOS manufacturer. Check your motherboard manual for exact codes.

When to Take It to a Shop

  • Burning smell → stop using immediately, something shorted
  • Liquid damage → do NOT turn it on. Take to a shop
  • Physical damage (dropped) → internal connections may be loose
  • You replaced parts and it still does not work → professional diagnosis needed

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