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Okay, something quite bogus happened to me yesterday. When I left for work in the morning my desktop computer was working just fine. I checked some things on the internet and synched my pocket-pc and didn't notice any signs of impending doom. Then I went to the start menu and told it to shut down before I left, which it did with no problem.
Late last night I came home and my wife told me the computer was broken. I went over to turn it on, hit the power button, and nothing happened. The fan didn't kick in, it didn't start to boot up, just nothing. I unplugged and re-plugged all the connections, and nothing happened. I opened the case and found (aside from a lot of dust) that the LEDs on the motherboard were lit up and nothing obvious had come un-done. Still won't start.
My questions are as follows:
1) Seems to me like it's a power supply problem. Could I be wrong? Is there anything else that could be broken that would cause it to not even try to begin to boot up?
2) If it is a power supply problem, is the best way to fix it just to get a new case? I don't have a multi-meter or anything, and it's been long enough since my electronics classes that I don't know how good I'd be at rooting out and replacing the single faulty wire or component.
Thanks very much in advance for your help, Hatrack.
posted
There weren't any signs of trouble brewing prior to your computer completely failing to start yesterday? No crashes, slowdowns, or funny noises?
Posts: 5462 | Registered: Apr 2005
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None that I noticed. That's what surprised me. When I shut it down before work, it seemed to be tip-top.
Posts: 2804 | Registered: May 2003
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Usually when the LEDs are lit on the motherboard the power supply is good... I repair computers for the state and I have only seen one computer where it was the switch. Most of the time it is the motherboard. First I would unplug the power until the light on the motherboard goes out, this can take about 10 seconds, and then plug it back in and try it. They do sell power supply testers if you want to try that, but if the light is on the board is getting power. It could still be the power supply if only some of the pins are bad, or if it is giving out faulty power, but it is doubtful.
Posts: 14 | Registered: May 2005
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Okay, so it might be the motherboard? How could I tell for sure? Or how do I know whether the power button is broken, and how would I go about replacing or repairing it without throwing out the entire case?
Does this sound like something I could fix myself, or should I get some professional help involved.
Thanks again for the tips, everybody. Posts: 2804 | Registered: May 2003
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It's just a tiny momentary switch, and I can't remember offhand if/how you'd replace it. But it shouldn't be too tough. Or, it could be undoable.
Posts: 5462 | Registered: Apr 2005
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I remember trying to look at the power switch last night and I had a hard time getting to it. But it does sound like a solution that would make sense, so I'm going to go pull apart my box and see if I can get at it. I'll check back in here soon though if anyone else has any other ideas or suggestions.
posted
Oh, it's a homemade computer with an Antec case. I actually figured out how to open the front so I could see the wires that went to the power button. It wasn't nearly as hard as I thought it was last night. I can't see any problems, but I'm not sure what I'm supposed to be looking for either. Maybe I'll just unplug it from the motherboard and take it in to Staples or something.
Posts: 2804 | Registered: May 2003
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While working for the state, most of our systems are under warranty, so if we have a problem like this the first thing we do is replace the system board. It seems like every time an agency buys a new model of computers it has a problem with one particular component. We have quite a few where it is the motherboard. We have one in particular that does the same thing yours does. It is caused by blown or raised capacitors. Usually from overheating, either because of the design of this particular model, or a series of bad capacitors. Here is a link to a site with pictures of blown capacitors. You could also do a google search. We also have another motherboard that gets blown caps, but it only makes the system reboot randomly. I haven't figured out how they are still working before we go to replace it for rebooting. You might want to check for blown capacitors, but it could also be something you can't see on the motherboard that is bad.
The switch plugs into the motherboard, and the motherboard sends the signal to the power supply to turn on. When we had a bad switch you could tell by pushing it that it wasn't clicking right. What kind of computer is it? You may see if that model or brand has a common problem with this sort of thing.
Hope that helps.
(ok so not a particular brand, but you could still do searches on the case, and the system board)
Posts: 14 | Registered: May 2005
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Thanks for that link. It was really helpful.
I checked the motherboard, and I couldn't see any capacitors with obvious external damage or any other problems. On the other hand, the power button sounds and feels just like it always did. So I don't know which one to try to replace. Maybe I'll just have to use this as the excuse to upgrade that I've been looking for.
Which leads me to another question. If I were to go find a new case or motherboard (which would probably also lead me to finding a new processor and memory), is there a good local store to go to? CompUSA? Staples? Radio Shack? It's been so long since I've gone component shopping (and I've never gone alone or in Albuquerque) that I don't even know where to start. I know I could probably get better deals online, but I'd kind of like to fix it in the next day or two if possible. If not, what's a good online dealer?
Posts: 2804 | Registered: May 2003
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NewEgg. It's generally heads and shoulders above its competition. Here in Madison, the local CompUSA has better parts than its rivals, but that varies widely by region.
Posts: 37449 | Registered: May 1999
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I don't know about local stores there, hopefully someone else will, but I usually order from www.newegg.com/. I do know that CompUSA has parts, but I haven't been there in a few years (the closest one to me is about 100 miles) so I don't know what they have now, or how their prices are. The other problem you will run into if you replace the motherboard, unless you get the same motherboard that is in your system now, you will have to reinstall windows. If you have XP hopefully you can do a repair on windows instead of a full reinstall. Another link on this.
If it is just the power supply you can get those separate from the case, and it is usually pretty easy to change (only 4 screws or so).
Posts: 14 | Registered: May 2005
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I second what WhtTigress said. I just fixed a computer with a very similar issue. At first I thought it was the power supply (in my inexperience), and then I realized it was the motherboard. I should have known better.
If you have another computer, you can try switching the power supply. It requires about the same skill as replacing a CD?DVD Drive. Just remember where you plugged in everything.
If you do end up buying a new power supply, I recommend you make sure that it is 20 pin 24 pin compatible. There is a big chunk of wires you plug into your motherboard. My computer has a 20 pin receptor. I had to buy a new power supply last week. The person at the local store assured me the one I got was universally compatible. I took it home and it had 24 pins...grr.
Most 24 pins are universal. You can clip off one end of it (4 pins). . I returned it and got a nice power supply at Best Buy (was a little expensive). I made sure it was the 24/20 pin, incase I ever want to upgrade my motherboard. My old power supply/fan would never have worked on a newer motherboard--since it was ONLY 20 pin.
Moving on. If you get a new motherboard, you may have to upgrade your power supply. If your computer is older, then most likely your power supply will be 20pin and your new motherboard will require 24 pin.
If you replace your motherboard, you can keep the same processor, just make sure your motherboard is for the same type of processor. Motherboards are processor specific. There are Intel Motherboards and AMD motherboards. An AMD chipset will not work on the Pentium board and vice versa. ( I get use Pentium and Intel interchangeably because I always get them confused-Sorry)
If you decide to go with a new motherboard AND a new processor, I recommend the AMD. They are cheaper, cooler (temperature), and comparable in speed--if not faster.
Posts: 2445 | Registered: Oct 2004
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I'm typing this post from my new (or good-as-new) computer. Just wanted to tell everyone thanks for the help.
I found a local part retailer and took the computer down. I told them what I'd tried, observed and suspected (much of which I got from this thread) so they wouldn't think I was a sap. They wanted to keep it for two days to diagnose it, but I said I just wanted to try out some parts and fix it myself. They also thought it was the motherboard, but I wanted to rule out the power supply first, so they brought out a new one and plugged it in and... voila, the comforting hum of a booting computer.
So I bought the power supply for $50, took it home and replaced it, and now my computer is back to its old self again. Oh, how I missed it.
Many thanks again to everyone for your help. And I do think I'm going to do a processor/motherboard upgrade before too long, so I'll keep this threat around as a reference.
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