How do I figure out what's preventing my computer from turning on?

Question

My old computer won't start. I've tested the CPU, and the motherboard works, so I can rule those two out. So that means it's one of 3 things; the RAM, the processor, or the controller. But my problem is I don't know how to determine the issue. Also, when I plug the computer in, there is no light coming from the power button in the front. The CPU doesn't have a switch either. If it matters, I'm using a Dell Dimension 8250.

Answer 1

Your description and labels are a little confusing. You said you tested the CPU and Motherboard and they work. How did you test those?



Then you say that it must be one of 3 things: either the RAM, the processor, or the controller. Isn't the processor the CPU (that you said you tested)? If not, then what "processor" are you referring to? Also, why could it not be the video adapter or PSU that's causing the problem? Why just those 3 things?



Then you say that there's no light when you plug the computer in. But you fail to mention if you can hear the computer powering on (fan noise, any beeps, etc). Is it dead silent when you plug it in...or does it make noise but just no light at the front? These are important facts to know to give you accurate suggestions.



Finally...you mention that the CPU doesn't have a switch. I've never seen any CPU come with a switch. All CPU's get inserted in their respective CPU slots (ZIF sockets usually). There's never been a "switch" for CPU's. What switch are you talking about?



I'm not trying to be a smart aleck...I just want more accurate info to help you better and not waste time with irrelevant suggestions.



ADDITIONAL DETAILS:

Thanks for supplying more info. I would say that the problem is either a faulty PSU or a faulty Motherboard. Even though you are getting a green light on the Motherbaord, doesn't mean that the Motherboard is okay, or that the PSU is working 100% correctly. Also, is the internal PWR wire plugs connected to the correct PWR pins on the Motheboard (the pins near the Reset and HD LED, etc)? I'm talking about the wire that goes from the power button of the case, into the PWR pins on the motherboard...nothing to do with actual PSU power plugs. If that's not the problem...then we're back to a faulty PSU or faulty Motherboard. The cheaper test would be to change the PSU first to see if the problem is resolved. If not...then it's the Motheboard, and probably not worth fixing since it's a proprietary piece of hardware that Dell will charge you like it's made out of gold.

Answer 2

It's a dreadful way to start a day - you press the power button on your computer and nothing happens. Few computer problems are more frustrating than when your computer won't boot. There are many reasons why a computer won't turn on and often very few clues about what might be the problem. The only symptom is usually the simple fact that "nothing works" which isn't much to go on. Add to this the fact that whatever is wrong could be an expensive part of your PC to replace - like the motherboard or CPU. Do not fear because all may not be lost! Follow these steps to determine why your computer won't turn on. Difficulty: Average Time Required: Anywhere from 10 minutes to a few hours or more depending on why the computer won't turn on Here's How: 1.Try to relax! There's a good chance you can figure out exactly why your computer won't start and then get it back up and running. I don't usually a troubleshooting guide with the same advice a psychologist might give a client, but when faced with a computer that won't start most people tend to panic, worried that all the data on their PC is gone forever. It's true that the most common reason a computer won't start is because a piece of hardware has failed or is causing a problem. However, that failing hardware isn't usually a hard drive, meaning that all your data is probably safe - just not accessible. 2.Computer shows no sign of power at all. Try these steps if your computer will not turn on and is showing no sign at all of receiving power - no fans running and no lights on the computer case. Important: You may or may not see a light on the back of your PC depending on the kind of power supply you have and the exact cause of the problem. Note: Don't worry about the monitor yet. If the computer is not turning on because of a power issue then the monitor certainly can't display anything from the computer. Your monitor light will likely be amber/yellow if your computer has stopped sending information to it. 3.Computer turns on for a few seconds and then turns off. Follow these steps if, when you turn your computer on, it promptly powers back off. You'll probably hear the fans inside your computer turn on, see the lights on the front of your computer turn on or flash, and then it will all stop - always before the boot process is complete. You may or may not also hear beeping coming from inside your PC. Note: As in the previous scenario, don't worry about what state your monitor is in. You may have a monitor issue as well but it's not possible to troubleshoot it quite yet. 4.Computer turns on but nothing shows on screen. If your computer seems to be receiving power after turning it on but you don't see anything on your monitor, try these troubleshooting steps. In these situations, the power lights will stay on, you'll likely hear the fans inside your PC running, and you may or may not hear one or more beeps coming from the computer. This situation is probably the most common in my experience working with computers that won't start. Unfortunately it's also one of the most difficult to troubleshoot. 5.Computer turns on but stops booting during the POST. Use this guide when your computer powers on, shows at least some information on the monitor, but then stops for any reason during the Power On Self Test. Use this troubleshooting guide primarily if you receive a BIOS error message during the POST but also if your PC locks up during the POST without an on-screen message. Important: If you're having an issue during the loading of the operating system, which occurs after the Power On Self Test is complete, see Step 6. 6.Computer turns on but an error message prevents the operating system from loading completely. If your computer begins to load Windows but then stops booting and displays an error message, you're best bet is to troubleshoot the problem based on the specific error message. If you don't find instructions on resolving the specific error you see, see the first tip below for information on requesting more assistance from the forum on this site. Tips: 1.Still can't get your computer to turn on? Let a community of computer support enthusiasts help out! Post the details of your problem in the PC Support Forum. 2.Did I miss a troubleshooting step that helped you (or might help someone else) fix the cause of a computer not turning on? Let me know and I'd be happy to include the information here.

Answer 3

1) Remove the power cables from the computer, then remove the battery from the system board, it is about the size and shape of a quarter. Allow to sit for about four minutes.

Leaving the battery out, try to power it up, does it boot now?



No?



Remove everything from the computer, like RAM, video card and so forth. Just leave the processor and it's fan.

Turn on, does it beep? Yes, it is a signal that the system board does function.

Now install some ram, does it continue to beep? Yes,

install the video card..

Anything on video?

Answer 4

Sounds like a dead PSU.

Remove all of the RAM. If the computer powers up and beeps, RAM is a prime suspect.



Good Luck