Hardware
Windows PC won't power on
No lights, no fan, nothing on screen. Work through power, cabling and the front-panel reset before assuming the machine is dead.
Read before you start
Unplug the machine and hold the power button for 30 seconds before opening anything. Never work inside a desktop that is still connected to mains power.
This guide is for you if
- Nothing happens when you press power
- Fan starts for a second then stops
- Power light blinks but the screen stays black
Step by step
Work top to bottom0 of 6 steps done
Test the outlet and the cable
Plug a lamp into the same outlet to confirm it has power. Then swap in a known-good power cable or adapter. On a laptop with a removable battery, try charging with the battery out.
A charger with a faintly glowing LED can still be dead — swap it rather than trusting the light.
Drain the residual charge
Disconnect the power cable, hold the power button down for 30 seconds, reconnect and try again. A stuck power state looks exactly like a dead machine.
This one step fixes a surprising number of 'dead' laptops.
Strip it back to the essentials
Unplug every USB device, dock, monitor and memory card. Power on with only the power cable connected, then add devices back one at a time.
A shorted USB device can stop a machine from powering on at all.
Watch and listen for a pattern
Count the beeps or note how the power light blinks, then look that pattern up for your make and model. A steady fan with no display and no beeps usually points at memory or the board.
Reseat the memory
With the machine unplugged, open the case, release the clips and reseat each RAM stick until it clicks. If it still will not boot, try one stick at a time.
Work on a hard table and touch bare metal first to discharge static.
Book a bench diagnosis
If it still will not start, the fault sits in the power supply, board or display assembly — all parts-level jobs. Bring the charger; a large share of 'dead' laptops are charger faults.