Laptop power problems

This is a Style Guide for the Restart Wiki

Summary

This page deals with laptops that won't power-on, or immediately or randomly power-off again.

Diagnosis

A faulty power supply or battery is a relatively common problem with laptops. Your first aim should be to try and determine which, if either, is at fault.

Most if not all laptops will run happily with no battery, so long as they are plugged into the mains. Take out the battery and see if the laptop will run just on the mains adapter. If so, the battery is almost certainly dead or dying.

Conversely, see whether the laptop will run on the battery alone. If so, the problem is with the mains adapter or its lead, or the power socket on the laptop.

Some laptop power adapters have a power light. If this remains extinguished, the adapter is almost certainly dead. But before discarding it, check the fuse in the mains lead, and check that the mains lead itself is serviceable.

There are many different types of laptop mains adapter, but manufacturers tend to use one type for a range of similar models. It's well worth asking around to see if you can find someone with a laptop using the same or a similar adapter that you could try. Firstly, make sure the plug is the same size. (A slightly oversize plug might damage the socket on the laptop.) Next, examine the label on the adapter and make sure its output voltage is the same, or at least within 1V. Lastly, make sure it's output current (in Amps) or power (in Watts) is the same as yours or greater.

Problems can be caused by a fault in the lead from the power adapter to the laptop plug, particularly if this lead has been habitually wound around the adapter body. Try bending it at various points, particularly in the region of any kinks, and close the the adapter itself and the plug at the other end.

The power socket in the laptop can also get damaged. Try wiggling the plug in the socket to see whether that has any effect.

If you are unsure of the state of the battery, a small utility [BatteryInfoView] will display the status information held in the chip included in all laptop batteries.

If you still haven't located the problem, then it may be a fault on the motherboard. By all means disassemble the laptop to see whether there is anything obvious, such as any components which have clearly overheated or physical damage. If the laptop powers on but immediately powers off again, it could be that the heatsink is no longer making efficient thermal contact with the processor, allowing it to overheat and automatically shutdown.

Safety

Battery safety Dodgy far-eastern adapters Don't open the adapter

External links

• External links as bullet points