Why does my computer turn off shortly after starting?

Answer 1

Assuming the household mains supply is not affected, unexpected power interruptions can usually be traced back to the computer's power supply unit (PSU). The computer's PSU should therefore be inspected. If the fan and grill are caked in dust, disconnect and completely remove the PSU and, with some newspaper laid out on the work surface, use a small paintbrush to loosen the build up. A small vacuum can be used to suck any debris out of the casing. Cans of compressed air are not recommended as this requires the PSU casing be disassembled, which will invalidate any warranty conditions that still apply. However, if using compressed air, ensure the water content is minimal (lens cleaning grade is recommended).

While the machine is open, carefully remove any dust and debris from the vents, fans and all components inside the outer casing. Use caution with vacuum cleaners as static electricity can destroy memory chips (you can buy special vacuum cleaners specifically for this purpose). If the build up is heavy, it is best to remove each component to give a more thorough cleansing. Use small brushes as much as possible, but if compressed air is required, use it from a good distance.

Once free of debris, re-install all components and ensure all connections are restored and seated correctly. All connections are keyed so they will only fit one way, however there may be a large number of connections. It's worth taking a few snapshots prior to disassembly to ensure you know exactly what goes where. Note that some plugs may not be required (there are often spare connections provided for future expansion). If any plugs are damaged, use an unused connection instead, but ensure all cables and connections are fit for purpose and that there are no shorts (crossed pins). Ensure all cables are routed away from fans and that all fans spin freely.

With everything reconnected other than external peripherals (screen, printers, etc), plug into the mains and turn on. Inspect the fans to ensure they are all spinning freely. If all is well, then you should be good to go. Power down and complete the re-assembly. However, if there are any problems, ensure everything has been reconnected properly and try again. If fans fail to spin and they are connected properly, replace them.

If the power issue persists, then the PSU is likely faulty. If it's out of warranty then it's not worth spending money getting it looked at, so just replace it. When buying a replacement, try and get the exact same make and model. Otherwise ensure all the regulated voltages match the original. The wattage should be the same or higher (you might get away with a slightly lower wattage, but its best to play safe). Also ensure the wiring loom has sufficient connections and that the motherboard connections in particular exactly match the existing PSU. Note that a 24-pin connection may be split into a 20-pin with an auxiliary 4-pin to suit both types of motherboard. However also note that graphics cards (including motherboard graphics) often require a separate 4-pin connection.

Another cause of unexpected power interruptions is an overheating CPU (central processing unit). However, having already cleaned all the components this should resolve the problem. If not, the CPU cooler probably needs replacing (the fan has either stopped working or is not spinning fast enough). If not covered by warranty you'll have to replace it yourself or get someone to do it for you.

The CPU cooler consists of a (large) metal radiator and fan that sites directly atop the CPU. The entire assembly should be replaced with a matching assembly. You will also need to clean the existing thermal paste off the CPU to ensure a clean contact with the replacement radiator. Most coolers come with a thin coat of thermal paste, ready to assemble, but if not there will either be a small tube of thermal paste provided or you can buy your own. Use as little as possible and spread thinly and evenly to ensure a clean contact with the CPU contact plate.

If having done all this and the problem still occurs, the motherboard itself is the next likely suspect. Again, if not covered by warranty, you'll be on your own. Depending on the age of the motherboard, it's often better to dig deep and upgrade the motherboard, CPU and RAM all at once. Most people will do this as a matter of course every 3-5 years as the performance boost alone is well worth the expense. However, if the CPU and RAM are fairly new, replacing the motherboard with the same or newer model is the cheapest option. The only thing to be aware of is that the available connections match or better the existing board and that it is suitable for both the CPU and the RAM.

Answer 2

When I push the power button i can hear it turn on. An ASUS screen pops up (The screen that says push F2/Del to enter BIOS setup(?). Then a screen showing the hard drive and disk drive shows up with CTRL+m to enter a menu. Then it goes back to the ASUS Screen, then to the windows four squares then shuts off. I'm using Windows 8

Answer 3

Umm not particularly a good thing you could have an extreme virus you may need to have it looked at by a professional.

Answer 4

Power supply.