A lot happens after you push a power button, even before you see the “splash screen.” Electronic devices—computers, tablets, phones, PDA’s (remember them?), even appliances, go through a Power On Self Test, or POST. In basic terms, it is exactly what it sounds like. As the current is applied to the system board, the most basic components on the board perform functionality testing according to a set of instructions coded into them. This is a very basic explanation, but what the average computer user needs to know about this process is that your computer is running simple tests on the system-level components to see if they can work. Today’s POST processes are often set to silent-unless-something-is-wrong, but they can produce one single beep at the end of the process, indicating All Is Well.
The good thing is that a certain number of beeps indicates something is NOT well. The bad thing is that the number of beeps and what they mean is not universal. Motherboards are manufactured by a lot of different companies, and they’re the ones that determine what a given series of beeps means. But for the most part, if you’re getting beeps from your at startup, and you haven’t been getting beeps at startup all along, you can write the beep sequences down and either search out on the internet what they mean and try to fix it yourself (hang on, some stuff you really can fix yourself) or at least tell a technician on the phone what you’re hearing. It’ll give him a starting point.
If your keyboard isn’t plugged in all the way, your motherboard is not going to be happy, it will beep at you. If you have a stick of RAM, your computer may beep at you or it may not start at all; there are a few things that can determine what will happen with bad RAM. If it’s RAM, you can try pulling it out and sticking it back in firmly. Use the little “wingie thingies” at each end of the stick of RAM to release it, and pull out one stick and try to start. (Obviously this is only a viable troubleshooting step if you have more than one stick of RAM installed.) Go through this process until you can say definitively that you know each stick is good or until you know you can’t tell. Usually, if you can’t definitively say one stick of RAM is bad, you don’t have bad RAM.
Today’s computers don’t make a big deal out of the POST process. That’s a signal of our technology progress, we can just trust that they’ll let us know if they need our attention.