how do I figure out what's overheating?

[John P.]

My system will just completely power off after about 10-15 minutes of
running, but I can open up the case side and put a box fan blowing directly
on it and it will run for as long as I want. It's been working fine for
about a year and just started doing this about a week ago. Unfortunately
both the front and rear fans are spinning as well as the one on the CPU and
the powersupply so I'm at a loss as to how to figure out what's
over-heating... and unfortunately I do not have any spare parts to try... is
there anything else I can look at or check to help locate the problem? I
really don't have the cash laying around to start replacing things.

 

[Paul]

My system will just completely power off after about 10-15 minutes of
running, but I can open up the case side and put a box fan blowing directly
on it and it will run for as long as I want. It's been working fine for
about a year and just started doing this about a week ago. Unfortunately
both the front and rear fans are spinning as well as the one on the CPU and
the powersupply so I'm at a loss as to how to figure out what's
over-heating... and unfortunately I do not have any spare parts to try... is
there anything else I can look at or check to help locate the problem? I
really don't have the cash laying around to start replacing things.

Speedfan can give you some temperature readouts, but that won't tell
you everything.

http://www.almico.com/speedfan440.exe

(screenshot)
http://www.almico.com/images/mainwindow.gif

The computer should have a sensor for the CPU, and perhaps
one for the motherboard or chipset. The HDD may also have a
temperature readout (but that isn't going to shut down the PC).
(You can't believe the labels in Speedfan - it knows there are
sensors, it reads them out, but the label as to which does what,
might not be correct. Sometimes two sensors will be swapped.)

So you can at least check the CPU temp and see if it is over 70C.

Some older computers use a separate chip to monitor overtemp. My
S462 AthlonXP motherboard had an 8 pin DIP chip, whose only job
was shutting off the computer if it got too hot. That chip connected
to a diode inside the CPU, as a means to monitor the temperature.
Sometimes, a chip like that can be mis-adjusted, and is tripping
at too low a temperature. On modern systems, a more reliable
scheme may be used, where the "THERMTRIP" signal comes right from
the CPU itself. So the CPU tells the motherboard in that case,
when it wants the power shut off.

Paul

 

[John P.]

Speedfan can give you some temperature readouts, but that won't tell
you everything.

http://www.almico.com/speedfan440.exe

(screenshot)
http://www.almico.com/images/mainwindow.gif

The computer should have a sensor for the CPU, and perhaps
one for the motherboard or chipset. The HDD may also have a
temperature readout (but that isn't going to shut down the PC).
(You can't believe the labels in Speedfan - it knows there are
sensors, it reads them out, but the label as to which does what,
might not be correct. Sometimes two sensors will be swapped.)

So you can at least check the CPU temp and see if it is over 70C.

Some older computers use a separate chip to monitor overtemp. My
S462 AthlonXP motherboard had an 8 pin DIP chip, whose only job
was shutting off the computer if it got too hot. That chip connected
to a diode inside the CPU, as a means to monitor the temperature.
Sometimes, a chip like that can be mis-adjusted, and is tripping
at too low a temperature. On modern systems, a more reliable
scheme may be used, where the "THERMTRIP" signal comes right from
the CPU itself. So the CPU tells the motherboard in that case,
when it wants the power shut off.

Thanks, I'll check the BIOS tonight to see what sort of diagnostics it has
and I'll give that software a try... hopefully I'll get lucky!

 

[Flasherly]

"Paul" <[email protected]> wrote in message

Though not under a load (PRIME 95 software's torture, or system level
technician's tests), the BIOS is generally the first screen consulted
after a system build. F2 at boot and under the appropriate MD chipset
option for a readout of the core temps and voltages (too). Leaving it
there 15, 30 minutes isn't a bad idea.

Recently had a LG DVD unit I suspect was either PS draining voltages
or may have ruined it. Winders of course doesn't want anything to do
with that stuff, and flat out got weird. Yes, it was showing a
problem in the BIOS voltages.

Disassemble and clean out any dust bunnies or parakeet feathers.

Reseat the CPU/Heatsink junction (if possible) and use a long straight
razor to spread a well regarded thermal compound correctly, as thin as
possible. Hardly splurging for a quality CPU/heatsink fan, at $20ish.
Not sure what or who built your equipment. That you can point fans
may potentially be an indication of poor efficiency case design.
Things to look for, and I'm also an avid user of SpeedFan. Always
want to know what the temperatures are doing.

Computers are known to age and develop problems, more or less
gracefully depending on the quality of build components and service,
nor is it unreasonable not to suspect the OS, over time, which may
have a couple oddball instances of poor programming throwing
curveballs -- the Winderz way of getting a tad cantankerous from
(inept and conflicting) subsequent installs.

No spare parts. Don't work that way. You want to play the game, you
flatout ain't gonna get away with not paying a little token
something. Ranging to downright dirt cheap, depending on abilities
and expectations.

 

[Paul]

Thanks, I'll check the BIOS tonight to see what sort of diagnostics it has
and I'll give that software a try... hopefully I'll get lucky!

If it isn't a CPU temperature problem, it could always be the
power supply which is shutting things down. They have protection
features and can do that if there is a problem.

Do you have to toggle the power switch on the back of the system,
to get it to start again ? And if so, if the system is still warm
and you run it again, does it shut down faster the second time ?

Paul

 

[Bug Dout]

get a can of compressed air
Good.

open you to get to the components and
spray each them and see which one is hot

Eh, why bother. Use the can of compressed gas to clean out ALL the
intake openings, they've clearly gathered dust and junk and even though
your fans are running they're not moving much air through the case
interior anymore. So blow out all the openings and it will be a lot
happier. Don't waste time trying to figure which component is hot and
bothered, the whole interior is too hot. While you're at it, blow out
the heat sink on the CPU and its fan.