The sudden unexpected shutdown of an operating laptop computer has three common causes among others.
- The power-supply transformer or adaptor is going bad, causing the power supply itself to shutdown
- A cooling fan has quit working, causing the laptop to thermally shutdown
- Lint has collected on the cooling-fan screen guards or in the cooling ducts, causing the laptop to thermally shutdown from lack of adequate air flow
The first two causes and fixes.
The first cause does not happen often. But, to check it or to fix it quickly, a spare power adaptor will do both. The spare will also eliminate this possibly if these shutdowns keep occurring while it is connected. That leaves the two other causes.
The second cause has a greater potential of happening, but not very often. One can lift the front side of the laptop to see if the cooling fan (usually on the bottom side if the laptop) is rotating all right. Many laptops have two fans. If these fans are rotating all right, that leaves only one other common cause. If not, then the nonfunctioning fan(s) must be replaced. This replacement can be self-done, but it requires disassembly of the computer. This disassembly is not easy because the laptop has several ports and accessories tightly fitted into its chassis. A repair shop can do it much easier.
The third and most common cause and fix.
The third cause (collected lint) is the most likely reason for the laptop shutdown. For one thing, the bottom-side cooling fans are close to the surface on which the laptop sits. There, the fans can suck up surface dust easily. This dust collects on the fan screen guards as lint, which prevents adequate air flow through the cooling air ducts. This lint also collects in the ducts themselves, but in smaller amounts.
To describe these ducts further, they pass over the metal heat-transfer sinks surrounding the central processor, which, in turn, allow the air flow to keep the processor at a safe preset temperature. If that temperature is exceeded, the laptop shuts down quickly to protect the processor. These air ducts usually vent from the back or from one side of the chassis.
The easiest and best two-step recommended way to fix this problem most of the time is simply
- to remove any lint collected on the fan guards
- to blow out the cooling ducts and fan boxes with a small canister of compressed air, starting at either end.
Some of the blown lint might collect on the insides of the fan guards, having been blown toward the fans from the duct vents. Yet many of these screen or mesh-like fan guards can be dislodged or popped from the chassis to remove this lint, and then wedged back into place when the cleaning is done.
This cleaning method is not new, but it works well here because only small amounts of duct lint will cause this shutdown problem. Once all the lint is removed, the laptop will work and sound much better for several months.
A canister of compressed air can be purchased at several outlets (camera, computer, electronics, and hardware). This problem can be further prevented by blowing out the fan and air ducts on a regular basis before the lint collects again. For more information on this and similar overheating problems, see these sites.