How to Identify Whether your Laptop is Running Too Hot

A laptop when new should run cool and operate correctly, but, over time the vents and fan may become blocked causing the CPU and other chips to overheat.
Even with a correctly venting fan it is possible for a chip or chips to fail and generate far too much heat. In this article I will help your determine if your laptop is overheating and suggest how the faults may be diagnosed. Only attempt repair if you are fully confident with taking the laptop apart and putting it together again as it is very easy to introduce another fault due to careless deconstruction etc.
You may notice any of the following that may be caused by an overheating laptop:-
1. The laptop may perform normally for several minutes then progressively slow down. This may occur because initially the CPU will be cool at turn on then get progressively hotter. Many CPUs have a ‘throttle back’ where once the temperature rises above a safe threshold the CPU will slow down so that less heat is produced by the chip.
2. The laptop cooling fan may come on after only a few minutes use then stay on most of the time. There is a sensor on the CPU that detects its operating temperature and when it becomes too hot will cause the fan to operate. The fan should cool the CPU and turn off. Some laptop fans run faster the hotter the CPU becomes, so if the vent is blocked will run very fast most of the time.
3. The laptop may lock up or crash usually after several minutes. This can occur if the CPU overheats.
4. The laptop may no longer power up with a display indicating that the CPU or GPU has overheated and permanently been damaged. There are many other causes apart from overheating but should be considered as a possibility.
5. Sometimes the laptop will not run or lockups up when operating graphics intensive programs. This can occur because as the graphic demand increases more heat is produced by the CPU and GPU. If this is not removed properly the laptop may crash or reset.
6. Hard drives can sometimes overheat inside the laptop. This will usually cause read/write errors or complete failure of the hard drive.
7. When a RAM chip overheats inside a laptop a blue screen error or lockup is usually caused.
Once you have determined that your laptop is overheating the next thing to do is to find the possible cause. The most likely cause is fluff blocking the cooling vent. To access this you will usually need to deconstruct the laptop, remove the heat sink and fan then clean the blocked vent. At the same time you may wish to check that the fan runs smoothly. Remember to add new extra heat transfer compound to the top of the CPU and GPU where necessary.
Assuming that the vent was not blocked then you will need to look for another reason for the overheating, here is a short list:-
1 Heat transfer compound not present, or heat transfer pads missing between the CPU and heat sink or GPU and heat sink.
2 The heat sink may have lost its heat transfer fluid, this transfers heat from the CPU and GPU to the cooling fins and sometimes leaks out.
3 The cooling fan may be jammed or sticking.
4. The CPU may be over clocked intentionally or unintentionally.
5 The GPU or CPU may be producing too much heat for the cooling system to remove as can occur when the chips are failing.
Some makes of laptops are on the verge of overheating, it is important to always use your laptop on a flat smooth surface. Do not use it on your lap though as often your knees will cover the air inlet vents.