[Ham-Computers] Computer shutting itself down

[WA5CAB at cs.com]

Dave,

I agree with Doc and Dale on the poser supply issue.  Go to a 450 or larger.

On the fan and airflow question, although I don't believe you have said 
whether you have a tower or desktop case, the mechanical layout of system boards 
and cases generally means that the heat pulled off of the CPU simply dumps into 
the case and usually has no other actual exit other than through the PS.  

I don't recommend mixing intake and exhaust fans in the same case except in 
the probably rare situation (which because of the PS fan this can't very well 
be) where the intake and exhaust fans are identical and the only air entry or 
exhaust is through them.  In my machine here, I discovered that the single 
intake fan was moving less air on it's own than what was flowing past it.  So it 
was actually restricting intake air.  This large tower case has mounting 
locations for two additional exhaust fans high in the rear.  So I replaced the front 
intake fan with two exhaust fans.

But your first step should be a larger PS.  And keep the 250 watt unit in 
case you ever have to haul the machine back to Gateway. 

In a message dated 4/28/2007 6:16:02 AM Central Standard Time, 
dcorio at zitomedia.net writes: 
>     Wow! Thanks for all the fast responses! Let me expand on the 
> situation a bit more.
> 
>     This PC has been a lemon since day one. So far, the hard drive has 
> been replaced three times, the motherboard has been replaced twice, the 
> CPU fan once, and the power supply once. Also, when the motherboard was 
> replaced, they used a 3.4 Ghz P-IV instead of the 2.6 Ghz that it 
> originally came with. All under warranty, thank goodness! It was shipped 
> with a 250-watt power supply, but I have added the following:
> 
>     NVIDIA TI-4200 video card with 128M of RAM (with a big honking fan!)
>     Soundblaster 24-bit sound card (also still using the on-board sound 
> card)
>     4-port RS-232  card
>     two to three USB devices
>     Added 512M of RAM for a full 1G
> 
>     All this requires power - and I suspect that the power supply just 
> isn't up to all I am demanding of it.
> 
>     I have tested the memory using a stress tester, in addition to 
> running the memory test at each startup. The CPU fan is clean and 
> unobstructed and working very well (it was just replaced by Gateway to 
> "fix" this shutdown problem). All vents in the PC have been cleaned, and 
> you could eat off the interior of the PC! I also did a Windows Repair 
> per Gateway's instructions in case it was an OS problem. (The OS is 
> Windows 2000 Pro, if I failed to mention that)
> 
>     If I don't ask much of the CPU, it will run forever without a 
> problem. However, if I put a demand on it, chances are it will shut 
> itself off. I run a program called "SETI at home" which does computations 
> when the computer is idle. Whenever I tell the program to use both of 
> the dual processors available in the P-IV, the PC will turn itself off.
> 
>     The machine never shuts itself off when I'm actually using it. It 
> waits until it is idle, then simply dies. No warning, no error message, 
> it simply turns itself off. There are no events logged at this shutdown, 
> although using the event viewer I can see the startup routines when I 
> restart it.
> 
>     The killer part of this is that while the CPU fan runs very well, 
> it's dumping the heat it vents directly into the power supply! There is 
> a great deal of heat coming out the back of the PC via the fan in the 
> power supply. If I hold my hand over the outlet of the CPU fan, I can 
> tell it is moving the heat very efficiently.
> 
>     I am thinking of just ordering a 450-watt power supply, but with 
> money a little tight right now, I want to be as certain as possible that 
> this will fix the problem. Replacing the computer is out of the question 
> at this time, and I also don't have another I can use.
> 
>     Sorry for being so long-winded, and thanks again - and in advance! - 
> for any and all help!
> 
> 73
> Dave
> KB3MOW
> 

Robert & Susan Downs - Houston
<http://www.wa5cab.com> (Web Store)
MVPA 9480
<wa5cab at cs.com> (Primary email)
<wa5cab at houston.rr.com> (Backup email)