Startup and POST errors can help you locate PC hardware problems.
- [Narrator] Hardware problems become most obvious when you start the computer, or not. In fact, the first problem anyone notices, is that the computer won't start. In that situation, the issue is the power supply. First questions: Is it plugged in? Does the wall socket have power? You can obtain a socket tester at any hardware store to determine not only if the socket has power, but confirm that it's wired properly. If not, plug a lamp into the socket and see if it turns on.
Check the power cord. Both ends must be plugged in. The cord must be in tact. Look at the back of the PC for a power supply switch. Ensure that it's on. Finally, listen to the power supply fan, is it whirring? If the PC still fails to start, this situation happens during periods of intense power usage, the layman's term is "brown-out", though it's more properly called a "dip". If that's the case, we just have to wait. Check the console, specifically look for it's power lamp.
Is it on? Can you hear the CPU fan which is different from the power supply fan? Tap the "Caps Lock" key. Does the Caps lock lamp illuminate on the keyboard? If so, the keyboard is getting power. That's a good sign. When the system has power, it begins it's power-on sequence. The first step is the Power-on self test or POST. The POST examines hardware and determines that everything is available and functioning. If the POST fails, you see a error message, such as "no keyboard", and if the video output doesn't work, you hear a series of beeps.
The POST also checks the system's internal configuration. This information is stored on a battery backed-up chip on the motherboard. If that battery fails, then you see a start-up configuration error. The error messages for a bad motherboard battery can vary. They could say anything from "a missing hard drive", to "no memory", or the system's date and time could be incorrect. The solution is the same, replace the motherboard's battery. If you are comfortable opening the PC's console, you can locate the coin-sized battery on the motherboard and find a suitable replacement.
If not, any computer repair shop will do the job for you. Generally speaking, the motherboard battery should last for well over six years. So, if you see a configuration error on a new system, it could be a sign that other electronics have failed. Now, if the POST passes, then an operating system is loaded. The major error at this point, which can induce heart attacks, is "Missing Operating System". That could mean a damaged hard drive, a botched Windows upgrade, or even a nasty malware infection.
To remedy the situation, you must start the PC in recovery mode, and attempt to repair Windows, or you can use a system repair disk to start the computer and repair Windows that way if the main hard drive is offline. These topics are covered in another movie. If the PC's primary storage device in Windows are having a good day, then the operating system continues to load. Eventually you see the sign-in screen, or if the system is in the middle of an update, you may see the updates installed, and then the system could restart again.
After you sign in, your user profile and other configurations are set, various startup programs run, and then you can stop trouble-shooting and start using the computer.
- Diagnosing the causes of PC issues
- Troubleshooting hardware and software
- Performing startup and system restore steps
- Accessing the Task Manager
- Using the Registry Editor
- Fixing Windows
- Maintaining storage drives
- Restoring network connectivity