The motherboard is an essential part of any PC. Think of it as the spinal column of your computer. In plain language, it takes the power input from the power supply and distributes it throughout the computer. In addition, the processor (the part that runs all commands in and out) is generally housed on the motherboard. When a motherboard goes out, in general:
- The computer will have lights like it is receiving power, but nothing will happen
- There may be physical signs of damage (aka popped capacitors) on the motherboard.
- The computer may not power on, but the data on the hard drive will be unaffected.
For consumer grade laptops and desktops, the rule of thumb is that it is often less expensive just to replace the computer than replace the motherboard. If in doubt, talk to your local IT pro.