Diagnosing the source of a computer problem usually involves a process of elimination, evaluating each part. In a desktop computer, this is easy, since each part can be removed or replaced with little difficulty. Taking apart a laptop isn’t quite so easy. Unlike a desktop computer, they aren’t really designed to be disassembled by the average consumer, and in many cases, taking apart a laptop can void its warranty.
How to Diagnose Without Disassembly
Obviously, since disassembly of a laptop is beyond the skill of most users, diagnosis of hardware problems requires the ability to recognize common problems that can be caused by specific computer parts. Overheating is usually a sign of a failed fan or heat-sink, rather than a problem with the computer’s processor. Constant crashing is a sign of bad memory much more often than a failed motherboard or processor. These little indications can be a lifesaver when dealing with sealed hardware like laptops.
When diagnosing whether it is the motherboard or the processor, there are a few basic things to look for. Processor damage is usually pretty obvious; the computer will completely fail to operate, unable to even run the BIOS (Basic Input Output System) firmware. This can also be caused by memory failure. Replace the memory with known good memory, and see if the problem persists.
Motherboard problems are a little more difficult to detect, as a motherboard is not a single piece of silicon. Typically, a motherboard failure is actually a failure of one of the components soldered to the motherboard, such as the USB controller, or the hard drive controller chips. But often, the problem is with one of the main controller chips on the motherboard, which will cause to the computer to stop functioning altogether. There isn't any good way to discern this from a processor failure, other than to replace the processor; this isn't always possible.
Problems With Laptop Repair
A basic problem with dealing with laptops is the fact that many laptops are built with the processor soldered directly to the motherboard rather than connected with a socket, like most desktop computers. This means that any problem with either the motherboard or processor will require the replacement of both. A side effect of this is that the motherboard and processor will have to be ordered as a single unit; you can't mix and match, and only the parts that the manufacturer of the laptop is willing to supply can be used.
To compound the problem, if the laptop is still under warranty, any repairs have to be done by the manufacturer, or a manufacturer-certified repair shop. This often will lead to a cost of parts and labor that will actually exceed the cost of the laptop, especially if the failure is caused by something that the warranty will not cover.
Finally, if the laptop is out of warranty, it may be altogether impossible to repair it, as most manufacturers do not stock parts for older machines that they no longer need parts on hand for warranty repairs.