Dead Computer Troubleshooting

Dead Computer Troubleshooting

One of the most difficult computer problems for a home user is troubleshooting a dead computer. When we mean “dead” we mean no signs of life at all. Where do you even begin? The average user doesn’t know the internal workings of their computer–and they shouldn’t have to. So when things go wrong, they do not know where to begin to diagnose and either fix the problem or make arrangements to have the problem corrected. The following steps will help give you some general knowledge of what could be wrong with your PC and give you some ideas on how to fix it or provide you with enough knowledge to prevent you getting ripped off at the computer repair shop.
For starters, if the computer is still under warranty, do not open the case, as this will void your warranty. HP, Dell and any other major manufacturer will respond quickly to your problems and arrange for you to send the computer in, or they might opt to send a technician out to work on the computer. If you bought the PC at a shop around the corner, send emails and begin a paper trail on the issue.
With that said, a completely dead computer will usually have either a bad motherboard, bad power supply, or a faulty case. The following steps will help you find out which is the culprit. Well start with the easiest and work our way down to the hardest. One of the first things you’ll want to do is unplug the computer and take it to a table where you can lay it flat. Open the case and check the connections to see if you notice anything blatantly wrong, then proceed with the steps below.

Diagnosing A Bad Power Supply

Power supplies can fail without warning. The worse part is, they can partially fail. This means you might be getting power to the motherboard, the fans and other components, but you do not have the correct voltages to start the motherboard.The power supply is located at the back of the case, and is where the power cable plugs into the PC.

1. Your first step should be to plug the computer directly into the wall and bypass any power strips. You should also confirm the outlet is working properly.
2. Make sure the red voltage regulator switch on the back is set to 115 if you reside in the United States, people in some countries will need to set theirs to 230. With the power off and unplugged, try toggling the switch to 230, then back to 115 to make sure it is seated in the right position.
3. Next, buy a power supply tester. Computer techs will use a multimeter to test for proper voltages. Normal users can just buy a power supply tester. These are cheap and easy to use.
4. If your power supply is bad, buy one of equal or greater power. If your current power supply is 350WT, be sure to get one that’s 350WT or higher. Shop for a power supply.
5. If you have an HP computer, read these HP power Supply troubleshooting tips.

A power supply will tend to fail before anything else, as they take the most abuse. They are the front line when a power surge or brown out occurs. The good news is, they are extremely easy to replace should you find this is the problem.

Diagnosing A Bad Computer Case

While a dead PC will either normally be a bad power supply or bad motherboard, the next easiest thing to troubleshoot is the case. How can a case go bad? A case has minimal smarts, but it does have wires leading from the power button to the motherboard that can go bad, and some even have advanced I/O panels that can fail.

1. You can try bypassing the case switch. This means you are initiating the power-on sequence without using the button on the front of the case. For this, you will need a good set of eyes and a small, flat-head screw driver. The idea is to find the wire leading from the power button to the motherboard that’s marked something like POWER SW or POWER ON. It will cover two pins on the motherboard. Carefully, with the computer plugged in, touch tip of the flat head screwdriver to both of those pins at the same time, thus “shorting” them. You will not get shocked by doing this, but you need to be careful not to scratch the motherboard. Read more on bypassing the case switch here.
2. If you have a Dell computer, read how to test a Dell I/O panel here.

Diagnosing A Bad Motherboard

The motherboard is the hardest thing to diagnose and replace. If your motherboard is proven to be bad, it must be removed from the case and replaced. Unfortunately, there’s a lot of stuff plugged into the motherboard, such as the CPU, RAM, PCI cards, Video Cards, hard drives, CD / DVD drives, power supply and fans. There are also tricky connections that must be made to the case’s power and reset switches. So replacing a bad motherboard is a long process. A bad motherboard will be determined by the following:

1. If all of the above are not the problem, the motherboard is the problem by default.
2. A bad motherboard might have visual signs of damage, such as bulging or leaking capacitors. See below.
3. With the computer unplugged, try holding in on the power button for twenty seconds. This will drain the capacitors of any excess power. The computer might start up and work fine forever. If the computer starts, then fails again after doing this, then the motherboard is bad.
4. Try removing any non-essential cards and drives in the computer. You do not need modems, sound cards, hard drives, CD / DVD drives, or floppy drives connected to boot. Our goal is to get a clean power-up situation, not boot into windows. If you remove non-essential parts and you still have no power, then the motherboard is bad.

In Conclusion, technicians will have more advanced tools and diagnostic equipment to quickly find the problem with your PC. But it will usually be one of the above that is causing the problem in a no power scenario.

Via (PCTech)