More often than not, when executing computer repairs, technicians often play detective. Playing detective generally involves utilization of the process of elimination. It is necessary to eliminate by testing to determine if a component is working correctly in order to be able to focus on the components for whatever reason may not be working correctly. The process of elimination saves time and gets our attention to the critical failure that is preventing the computer from functioning properly.

First we must understand all of the components that are required are required in order to make a computer work properly. We must examine physically the motherboard, RAM modules, processor, storage devices, and any type of cards for damage. If all looks ok, the next step is to check that all of it is connected and secured properly. Objects that connect directly to the motherboard must be seated tightly in their respective connectors. The power, and data lines for the storage devices must be connected and the unit secured to its attachments. Check that all connections to and from the motherboard are secure.

Once we have established that all of the hardware is present, connected, and secured, we can say that we have the necessary hardware. When we first press power on the computer, it does what is called a POST. A POST is a ( Power On Self Test ). If a computer fails the post, typically it will beep a couple of times and then do nothing further. A failed POST can be caused by bad hardware, incorrectly connected hardware, missing hardware, or hardware that is not compatible with the machine that you are working on. The trick is to find out what is it that is preventing the computer from starting up properly. Having other systems on hand with similar setups for testing makes this process simple.

For the process of eliminating the working components and determining what components are not working, I use a test machine that allows for me to remove the components from the machine that I am trying to fix and test them on a known working machine. I swap components between the boxes to determine what components work and which ones fail. A couple of possible outcomes can occur. You could find that all components from the machine that you are working on work. If this is the case, try to go connect and install the components in the box. Sometimes you may find that one of the components may not be compatible. If that’s the case, find a component that is, secure it and test it out. If you do in fact have a component that is at fault, test that component in a known working machine to confirm the fault. If the fault is identified, then you have successfully used the process of elimination to determine pre-POST where the failure lies.