The fan cannot turn the system off, or control its own speed, so there's no point replacing it--it's not bad.
There are two main possibilities. One is that the heatsink is mismounted, the CPU is rapidly overheating to the point of shutdown. This would also make the fan speed. It would be strange however, if it just suddenly started doing that, without being taken apart or something.
The other is a power problem. Certain motherboard power problems cause the fan controller to go to sleep, and the fan defaults to full speed. However, this most often results in the power light turning yellow but staying on. It might depend at what point in the boot cycle the problem arises. It might also happen if the 5V power supply comes up and shuts down, but again the light should be staying on yellow.
So unfortunately, there isn't just one answer, and it may be difficult to diagnose since it won't stay on. If you try to restart and it happens even faster, suspect the thermal problem. If it takes the same time every time, remove plugin accessories to see if one of them is causing it. If neither of those turn up anything, it's still pretty much a tossup whether PS or MB has a problem. PS is cheaper to replace on speculation, then if that doesn't fix it, either return it or keep it as a spare for future testing.
Message Edited by x_lab rat on 09-25-2008 01:13 PM
Well, I didn't know there was a "rule" about not posting service tags. This is my first time using this forum. I tried going to "Options" but I do not see anything about editing.
I appreciate your information regarding my dilemma. My son has been "tinkering" with this computer. so it makes sense what you're saying about the processor, etc. He won't admit to "removing" anything, but might after I show him your response. I will investigate this further. Hopefully, it will be a simple "fix".
Well bless his heart. I was a taker-aparter too. I usually managed to get stuff back together, but we didn't have computers when I was a kid.
The heatsink is that chunk of finned aluminum nearest the fan. It needs to fit down flat against the processor, not wobble or jiggle at all. If that has been taken apart, it is strongly advisable to take it apart again, wipe all the existing compound off both surfaces, and replace it with new compound. The compound is sold at Radio Shack or Frys. The instructions for removing the heatsink are in the online manual, along with illustrations.
If that's the problem, it would explain why the power light goes off instead of yellow like it typically would with a power problem.
Not posting service tags is a 'rule', but it's for your security. Someone with access to the database could get all your personal information from that, for whatever use they might make of it.
Message Edited by x_lab rat on 09-25-2008 01:29 PM
I'm happy that he has taken an interest in electronics and computing. I just wish it wasn't with our only computer - Ha. I actually have a bit of an IT background, but not enough in the hardware area.
We will pick up some compound and follow your advice.
I just want to say thank you for responding so quickly. You have been more than helpful and this is very encouraging. I will write back and let you know how we do.
Anything else you can think of, please let me know!
Nothing more about the cleaning and reinstallation. I don't want to make it sound more complicated than it is. Follow the instructions in the online manual, and on the compound as to how much to use and where to apply.
When I was a kid, I tended to take the TV apart. Dad got me a junk one to keep me out of the good one. I also had electronic experiment kits and they kept me busy for months. They still sell those at Radio Shack. They will make all kinds of gizmos you can take apart and make something else, again and again. Highly recommended for a tech-kid.
The junk TV can kill you if you touch the wrong thing, mom was always terrified of that, but obviously her concern was exaggerated, I'm still here. Computers aren't dangerous. Outside the power supply, there is no voltage over 12, which has no shock potential at all.
Message Edited by x_lab rat on 09-25-2008 03:46 PM
Hi. I wanted to get back to you regarding the heatsink issue. We cleaned off the old compound and reapplied fresh compound to the areas. The heatsink was then remounted and we made sure it was secure. Unfortunately, this did not resolve the problem. The fan still races and the system shuts down. Any other suggestions would be welcome, as I do not want to "trash" the pc. We've only had it a little over 2 years.
x_lab rat
2K Posts
0
September 25th, 2008 14:00
The fan cannot turn the system off, or control its own speed, so there's no point replacing it--it's not bad.
There are two main possibilities. One is that the heatsink is mismounted, the CPU is rapidly overheating to the point of shutdown. This would also make the fan speed. It would be strange however, if it just suddenly started doing that, without being taken apart or something.
The other is a power problem. Certain motherboard power problems cause the fan controller to go to sleep, and the fan defaults to full speed. However, this most often results in the power light turning yellow but staying on. It might depend at what point in the boot cycle the problem arises. It might also happen if the 5V power supply comes up and shuts down, but again the light should be staying on yellow.
So unfortunately, there isn't just one answer, and it may be difficult to diagnose since it won't stay on. If you try to restart and it happens even faster, suspect the thermal problem. If it takes the same time every time, remove plugin accessories to see if one of them is causing it. If neither of those turn up anything, it's still pretty much a tossup whether PS or MB has a problem. PS is cheaper to replace on speculation, then if that doesn't fix it, either return it or keep it as a spare for future testing.
laroth45
5 Posts
0
September 25th, 2008 15:00
Well, I didn't know there was a "rule" about not posting service tags. This is my first time using this forum. I tried going to "Options" but I do not see anything about editing.
I appreciate your information regarding my dilemma. My son has been "tinkering" with this computer. so it makes sense what you're saying about the processor, etc. He won't admit to "removing" anything, but might after I show him your response. I will investigate this further. Hopefully, it will be a simple "fix".
Thanks for your quick reply.
laroth45
5 Posts
0
September 25th, 2008 15:00
Never mind about the Options part of my reply. I was able to "edit" my original posting. Thanks.
x_lab rat
2K Posts
0
September 25th, 2008 17:00
Well bless his heart. I was a taker-aparter too. I usually managed to get stuff back together, but we didn't have computers when I was a kid.
The heatsink is that chunk of finned aluminum nearest the fan. It needs to fit down flat against the processor, not wobble or jiggle at all. If that has been taken apart, it is strongly advisable to take it apart again, wipe all the existing compound off both surfaces, and replace it with new compound. The compound is sold at Radio Shack or Frys. The instructions for removing the heatsink are in the online manual, along with illustrations.
If that's the problem, it would explain why the power light goes off instead of yellow like it typically would with a power problem.
Not posting service tags is a 'rule', but it's for your security. Someone with access to the database could get all your personal information from that, for whatever use they might make of it.
laroth45
5 Posts
0
September 25th, 2008 17:00
I'm happy that he has taken an interest in electronics and computing. I just wish it wasn't with our only computer - Ha. I actually have a bit of an IT background, but not enough in the hardware area.
We will pick up some compound and follow your advice.
I just want to say thank you for responding so quickly. You have been more than helpful and this is very encouraging. I will write back and let you know how we do.
Anything else you can think of, please let me know!
x_lab rat
2K Posts
0
September 25th, 2008 19:00
Nothing more about the cleaning and reinstallation. I don't want to make it sound more complicated than it is. Follow the instructions in the online manual, and on the compound as to how much to use and where to apply.
When I was a kid, I tended to take the TV apart. Dad got me a junk one to keep me out of the good one. I also had electronic experiment kits and they kept me busy for months. They still sell those at Radio Shack. They will make all kinds of gizmos you can take apart and make something else, again and again. Highly recommended for a tech-kid.
The junk TV can kill you if you touch the wrong thing, mom was always terrified of that, but obviously her concern was exaggerated, I'm still here. Computers aren't dangerous. Outside the power supply, there is no voltage over 12, which has no shock potential at all.
laroth45
5 Posts
0
October 9th, 2008 12:00
Hi. I wanted to get back to you regarding the heatsink issue. We cleaned off the old compound and reapplied fresh compound to the areas. The heatsink was then remounted and we made sure it was secure. Unfortunately, this did not resolve the problem. The fan still races and the system shuts down. Any other suggestions would be welcome, as I do not want to "trash" the pc. We've only had it a little over 2 years.