How to Troubleshoot Common PC Hardware Problems: Part 1
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Should you just replace the component? Should you try software troubleshooting first? Has the component gone bad, or the motherboard? And what's with all this dust?!
In this article we'll go over some of the most common hardware problems, at least in my experience, and the best way to go about getting them fixed.
Problem: The Computer Won't Turn On ...
This is a common problem with some interesting solutions. Often overlooked, some solutions can be the most simple.
There are two main symptoms to take into account before going too far into the repair: Is it the monitor or the computer that isn't turning on? It would be a shame to start opening up a computer system to test for bad parts if it's the monitor that's the problem.
If the tower turns on, and the monitor does not, the first step should be the most obvious, but is often overlooked -- check if it's plugged in. I can't tell you how many times I have come across a "frozen computer" that was simply a case of an unplugged mouse or keyboard.
Always take a second to try the most obvious things first. It could save you a lot of time.
Assuming everything is plugged in and properly seated, try plugging in another monitor to see if that one works; don't forget to try different power outlets as well, it isn't uncommon to blow a fuse, especially with more power hungry systems.
These steps should help you figure out if it's the monitor itself, the cable, a wall fuse, or possibly the graphics card/motherboard. If the second monitor works, you are likely dealing with a bad monitor. Unfortunately, in this case, there isn't much you can do. Most of the time, it ends up cheaper to replace the monitor altogether than to try to get it repaired.
If the monitor seems to work, but the tower doesn't turn on, the first thing you'll want to check is the power supply. A good test of this is to see if any lights turn on in the front or back of the tower. If they don't, the power supply unit (PSU) may be at fault. Some PSUs have a dedicated power switch, if it does, ensure that it is switched on.
Next you can open up your tower and look at the motherboard, most motherboards have a small LED (light) built in to show if power is running to the motherboard. If you can't find any evidence that power is properly running to the motherboard, you can either try using a PSU tester, or a replacement PSU.
It is not uncommon for PSUs to go out, so this is most likely the problem and a replacement is in order. Never try to open a PSU and try to repair it yourself, this is extremely dangerous; with replacement PSUs being so inexpensive, it really isn't worth the risk.
Problem: The Computer Turns On, But Still Doesn't Work ...
If you are able to see lights turn on and power is obviously flowing to the computer system and monitor, there may be a component issue. Whenever I deal with a computer "not turning on" or freezing up, I always like to follow a path running from the wall, to the monitor, and finally to the computer itself.
One thing to note when you first turn on the computer and the power comes on, is do you hear or see anything? Many times, the computer's Power-On Self-Test (POST) will let you know what's going on with the machine. If you hear any beeps, that is a great way to figure out what the issue is.
There are a variety of POST "beep codes" listed on the CompTIA A+ exam:
- Steady, short beeps -- The power supply may be bad, this is a good one. We tested the power supply to see if it turned things on, but what if it's not turning everything on? Or if the voltages are wrong? This POST test helps us narrow the cause down to the power supply. A replacement would usually be necessary.
- Long continuous beep tone -- Memory failure. This is usually what you hear when one or both of your Random Access Memory (RAM) sticks goes bad. If there is more than one stick installed, try taking one out first to see if the computer boots, if it does not, try with the other one. Usually, this will tell you which stick has gone bad, and you can replace or upgrade accordingly. If there is only one stick installed, you will need to replace or upgrade to fix the problem.
- Steady, long beeps -- This is another POST code that noted a bad power supply. The difference is, while the “steady, short beeps” code notes that the power supply may be bad, this POST code notes that is has gone bad.
- No Beep -- Not hearing a beep is also listed on the exam, and notes the most obvious resolution. Just like we went over in the beginning of the article, the A+ exam will expect you to know that no beep can mean that the power supply is not plugged in, or not turned on. This can also be a sign of the power supply being completely dead.
- No beep (system turns on and runs fine) -- This one is a bit elusive, but if you make sure to check every once in a while, you can save yourself some troubleshooting later on. If the system works fine, but does not beep once when you turn the machine on, your "beeper" may have actually died out. Under normal circumstances, most computer systems will beep one short beep.
- One long, two short beeps -- This POST code means that there has been a video card failure. Your first action should be to try reseating the video card, if any. This can sometimes solve the problem all together as some computer systems, especially those that are often connected to projectors, will move the VGA/DVI/Video cable so often, that it will actually slowly unplug the video card enough to stop working. If reseating the video card does not work, it may need to be replaced. Again, once you get into smaller, more complex components, the resolution becomes cheaper to replace than to repair.
More Troubleshooting Tips to Come ...
That's all for now! So far, we've covered what to do if your computer system will not turn on, how to troubleshoot the monitor and power supply, and how to properly identify POST codes and their meanings.
In part two of our Hardware Troubleshooting guide, we'll go over:
- the Blue Screen of Death (which you can also read about in my article: How to fix BSoD)
- what to do if your PC can't find the hard drive or operating system (OS)
- the CMOS battery and how to replace it
- reseating hardware and cables
- the effects of heat and dust on your computer's hardware (which you can also read about in my article: Understanding how PCs heat and cool