Symptoms of a defective and/or dying Processor, Motherboard and Power

What are the symptoms of a defective and/or dying Processor, a Motherboard and a Power Supply?  In practice how is each tested?

Hi MikeSA

An interesting question that could take a week or two to provide a full and complete answer…

However any of the malfunctions you mention could result in either a complete failure to work at all, no lights/LED's, absence of cooling fan activity, through non spinning up of hard drive, inability to enter BIOS, or just system instability.

Here's some thoughts on a strategy for testing the parts you mention (NOTE: this is not a diagnostic flow chart for ascertaining computer problems, but merely a strategy that could be implemented to check the components as set out in your question… PSU CPU and motherboard)

FURTHER IMPORTANT NOTE. No one who is not qualified or sufficiently experienced, and knowlegable about all the personal safety requirements and ESD precautions that should be taken should attempt any work of this nature. Lethal voltages are involved so if in any doubt, take the machine to a local competent computer technician or repair shop of good reputation and experience.

1 Start with the electrical outlet..(wall socket) is it delivering power and at the correct voltage and frequency for the equipment in use?

2 Follow the power  through to the Power Supply Unit (PSU) is it delivering the correct output on all rails? Often only relatively basic tests can be performed by the average home user as  more expensive test equipment  is usually required to correctly "load" the system to perform more advanced tests…… for this reason most folks are usually advised to do what a lot of local shops do (including mine) and that is substitute the suspect PSU for a known good working PSU of the corect output. This process of substitution is a well proven element in workshop diagnostic procedure and is routinely used in most repair shops, as it is quick, easy and simple to perform.

3 One of the first steps to take with motherboards is to carry out a visual inspection of all connections and focus attention on all the capacitors on the mobo…..(there may be a dozen or more) the tops should be flat…. any signs of exudate, or bulging from the top indicates a fault and that's bad news. Motherboard testers are available and will display an error code on a digital readout….. this code can then be looked up in the mobo tester instructions in an effort to pinpoint the fault. Checking for earth/ground issues can be assisted by checking correct positioning of "standoffs" and by removing the motherboard and connecting it up on the bench outside the body of the computer for testing purposes. Substitution with a known good working motherboard can also be useful (The presence of absence of a lit LED on the mobo is not in itself definitive)

4 Its not common for CPU's to fail (providing they have not been overclocked, interfered with in any way, and the cooling system, including fan(s) heatsink, thermal sensor and thermal paste has not broken down….) however substitution by a compatible known good working CPU or a new one can be a good plan to follow.

5 One of the reasons why substitution is so often used as a technique is that unless the machine can be coaxed into life, and shows some output to the VDU it's more difficult to ascertain other faults that may be present (RAM modules that have gone bad are often  one of the first things we check.)

6 It's appreciated that in the well equipped workshop there will be ample supplies of PSU's and other parts that can be quickly and easily substituted….. but this may be more difficult for the average home owner.

7 Once the machine is working… then its often wise to check if there are operating system errors (Windows) hard drive etc…. a useful tip is to boot from a Live distro of Linux (Linux Puppy is good) if the machine works well using Puppy then the finger of suspicion points towards Windows….

Post back if you need further information,

Regards

paws