The PC is completely dead: no lights, no fans
Safe checks for a machine showing no sign of life, and the point at which to stop.
Safety level: caution · Time: about 15 minutes · Level: beginner
Nothing at all when you press the button: no lights, no fan movement, no sound. Work through these in order — they run from most to least likely.
Applies to
Desktop PCs. A laptop that will not power on has a different first step: try it with the battery charged and the charger connected, and check the charger's own indicator.
Before you start
You will not be opening the power supply at any point in this guide. A PSU holds a dangerous charge long after it is unplugged, there is nothing user-serviceable inside, and opening one can kill you. If the checks below point at the PSU, the answer is to replace or test it, never to open it.
Steps
- Check the wall socket with something you know works — a lamp, a phone charger. Sockets and extension leads fail more often than computers do.
- Check the switch on the power supply at the back of the case. It is marked I and O. Knocking it while moving the machine or plugging in a cable is extremely common.
- Reseat the power cable at both ends. The kettle-lead end works loose surprisingly easily, especially if the machine sits against a wall.
- Try a different power cable. They are all the same standard lead; borrow one from a monitor or printer.
- Drain residual charge. Unplug at the wall, hold the power button for ten seconds, plug back in, try again. This clears a stuck power state and genuinely fixes a proportion of these.
- Check the case button. With the machine unplugged and the panel open, find the thin two-pin cable to the board marked PWR_SW. If it has come off, that alone explains everything. Reseat it.
- Look at the motherboard for a standby light. Most boards have a small LED lit whenever mains reaches the board. Lit means power is arriving and the fault is further along. Unlit, with a known-good socket and cable, points at the power supply.
Expected result
Either the machine starts, or you know whether power is reaching the board — which is the single most useful thing to be able to tell us.
If it does not work
At this point the likely causes are the power supply, the motherboard, or the front panel button. Distinguishing between them needs a tested spare supply, which is exactly what a workshop has and a home does not.
Stop immediately if
- You smell burning, or anything smells hot and sharp
- There is a scorch mark, or a bulging or leaking capacitor
- There was a bang, a flash or a smell of ozone when it last worked
- The machine has been near water or a leak
- There is any sign of rodent damage to cables
Unplug it at the wall and stop. Do not keep pressing the button, and do not try another supply — if something has shorted, powering it again can turn a repairable board into a replaceable one.
Bring it in. Diagnosing a dead machine takes us minutes with tested parts. Our diagnosis charge and turnaround are 700₹ for desktop and 1100₹ for laptop.
Read this next
- It powers on but there is no display — If it does light up but the screen stays dark.
- Power supply: wattage, connectors and why headroom matters — What a supply is meant to deliver, and which connectors should be seated.
- Track a repair or service job — A machine that stays dead after these checks needs a bench, not another attempt.
Still stuck?
If anything here does not match what you are seeing, stop rather than force it. Contact us · Book a repair
Last reviewed 2026-09-04.