The most common hardware problem is the power supply, in most cases the computer is worth fixing. The power supply can be replaced with a universal power supply that I keep in stock or in rare cases I can have a replacement in a few days. Second to power supply problems is cooling problems where dust will cause your processor fan to slowdown or stop. In most cases this will cause the computer lockup or freeze. I do stock processor fans. I do not stock other computer parts because of changes in technology, but have suppliers that came overnight parts if needed.