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Stroomproblemen met laptops zijn niet ongewoon, maar het is misschien niet duidelijk of het aan de batterij, de netadapter of de laptop zelf ligt. Hier vindt u de hulp die u nodig hebt.

Samenvatting

Als uw laptop niet aangaat, oplaadt of onmiddellijk of willekeurig weer uitgeschakelt, is het misschien niet duidelijk of de fout ligt bij de laptop, de batterij of de voedingsadapter. De hier beschreven eenvoudige tests vertellen u wat moet worden gerepareerd of vervangen.

Veiligheid

Alvorens verder te gaan, let op:

• Ongeschikte vervangbatterijen kunnen gevaarlijk zijn.
• Vervangende netadapters van slechte kwaliteit kunnen gevaarlijk zijn.
• Het openen en repareren van een netadapter kan gevaarlijk zijn.

(Deze punten worden in de onderstaande tekst verder uitgewerkt).

Diagnose

Een defecte voeding of batterij is een relatief veel voorkomend probleem bij laptops. U moet in de eerste plaats proberen vast te stellen welke van beide defect is.

De meeste, zo niet alle laptops, werken probleemloos zonder batterij, zolang ze op het lichtnet zijn aangesloten. Haal de batterij eruit en kijk of de laptop alleen op de netadapter werkt. Zo ja, dan is de accu vrijwel zeker leeg of stuk.

Omgekeerd, kijk of de laptop alleen op de accu werkt. Zo ja, dan ligt het probleem bij de netadapter of het snoer daarvan, of bij het stopcontact op de laptop. (Als uw accu al volledig ontladen is moet u misschien rondvragen of u iemand kunt vinden met een laptop met dezelfde of een vergelijkbare adapter die u zou kunnen proberen).

Sommige stroomadapters voor laptops hebben een stroomlampje. Als dit gedoofd blijft, is de adapter vrijwel zeker leeg. Maar voordat u hem weggooit, moet u de zekering in het netsnoer controleren, en nagaan of het netsnoer zelf bruikbaar is.

There are many different types of laptop mains adapter, but manufacturers tend to use one type for a range of similar models. If you need to try one which isn't identical to the original, firstly, make sure the plug is the same size. (A slightly oversized 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, especially if this lead has been habitually twisted or 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 failing electrolytic capacitors (see the capacitors page for details), or any components which have clearly overheated, or physical damage. If the laptop powers on but powers off again within a few seconds, it could be that the heatsink is no longer making efficient thermal contact with the processor, allowing it to overheat and automatically shutdown.

Repair

Replacement laptop batteries are available from a variety of sources, but the quality may be variable. In the worst case, a knock-off battery from an unscrupulous dealer and using a slightly different chemistry to the branded one could be a highly dangerous fire risk. Lithium batteries have a limited shelf life, so even a genuine branded battery might give poor performance if it's been in storage for a number of years. Wherever possible, always buy from a reputable seller, and make sure you can return it if it turns out to be faulty.

Replacement mains adapters, too, are readily available, but the same warnings about quality and safety apply. The best option might be to try and obtain an original adapter from another laptop of the same model that has died.

Laptop mains adapters are not designed to be repairable. Their cases are generally glued together very firmly as they would be highly dangerous if they came apart through an accident or incompetent tampering. For the same reason, whilst repair may not be totally out of the question, it must not be attempted unless you are completely competent in the repair and in securing the case again afterwards.

If the cable on the laptop side of the adapter is damaged it may be possible to cut out the damaged section, but you will need to take care to ensure that a replacement plug has the same internal and external dimensions.

If the power socket on the laptop is damaged, it may be possible to bend the springy metal leaves inside the connector in order to make better contact using a pin or similar tool.

In some laptops the power socket is connected to the motherboard via a flying lead, and the socket and flying lead may be available as a spare part. In others, it's soldered directly to the motherboard, in which case obtaining and fitting a replacement may be harder.

If you think the heatsink bonding to the processor may have failed, there are YouTube videos and other online resources showing how to clean off the old heatsink compound and how to apply the new. If you don't do it properly you could easily make matters worse.

Spare Parts

An eBay search will will throw up various sources of laptop batteries and mains adapters, but pay careful attention to the seller's reputation. If you purchase a replacement battery, make sure the vendor will accept returns in the case of poor quality parts.

If you search for a common replacement part such as a screen or keyboard, you will generally find several vendors who refurbish cast-off company laptops, and who may well be able to help with other parts such as a power socket.