From: Paul on
Paul Calcagno wrote:
> Thanks Paul. See my comments within your text below. Paul C.
> "Paul" <nospam(a)> wrote in message
> news:hn3b6v$ftv$1(a)
>> Paul Calcagno wrote:
>>> I'm running Win XP, SP3, 2 GB of RAM, Firefox, all WU's, Avira &
>>> SpywareDoctor set for updates and re-scans every day, MBAM, SAS,
>>> CCleaner resident on my Compaq laptop.
>>> Lately, sometimes right after I open up WLM and Firefox, the computer
>>> does an immediate shutdown - The screen goes black and the computer
>>> is completely off. Pushing the power on button brings it up just
>>> fine. This `shutdown' doesn't always happen.
>>> What I've tried so far is: "Dev Mgr==>Ethernet Properties. Click on
>>> Power tools tab; deselect `let computer turn off this device to save
>>> power". The only thing I didn't do after the Dev Mgr thing was a
>>> restart. Is there anything else that might cause/fix this problem?
>>> I've had some laptop fan issues, meaning that sometimes it seems to
>>> be off when it seems like it should be on. Would overheating the
>>> drive cause this kind of a shutdown? Would the `event logs' show
>>> anything and if so, how do I access them on my XP machine?
>>> Paul C.
>> Modern processors are protected by THERMTRIP. Once the CPU gets
>> over a critical temperature, THERMTRIP causes the computer to
>> switch off instantly. There is no time for any log entry, if
>> that is the nature of the problem. Such a shutdown does not
>> involve software at all, and it doesn't get a say in the matter.
>> Also, if the computer is getting that hot, the heat might not
>> be good for the battery. The battery lasts longer, if the ambient
>> temperature stays a bit lower.
> The battery's at the other end of the laptop so I doubt it's
> seeing much of the heat.
>> I would check the vent on the machine, to see if it is free of
>> dust bunnies. If you have pets, that only increases the odds
>> it is a problem with the vent.
> I've cleaned out the vent and the fan fairly recently. It seems
> that sometimes if I poke the fan (with a paperclip) it will start up.
> Doesn't do this all the time and I can hear it running at different speeds.
>> If you use a program like Speedfan (, you may be
>> able to monitor the CPU temperature.
>> It could be, that you have two fans, and one of the fans has
>> stopped entirely.
> Only one fan.
>> Paul

Brushless DC fans should be able to start on their own.

Fan speeds can be controlled by reducing the voltage. If
the voltage is reduced low enough, a fan may not be able to
spin. Since a fan with voltage control, is under feedback,
as the CPU temperature gets higher and higher, more voltage
would be applied by the driver or BIOS which is controlling
the fan. As far as I know, the fan should be able to start,
once enough voltage is present. If the driver was missing or
defective (in other words, there was no longer a control
algorithm working to control the fan), that could be enough
to leave the fan in an un-energized state. (This happened
recently to some unlucky Nvidia video card owners, due to a
defect in a recent driver update, so it does happen.) In the
case of your CPU, THERMTRIP is there to cover such a situation.

Inside the hub of the fan, is a small controller board.
That senses the position of the rotor, and controls when
the coils turn on. And that is supposed to guarantee that
the rotor can always be rotated. Now, maybe if there was
a problem with the control of the operation of the fan,
that would be enough to prevent proper operation. (I.e.
the transistor controlling one coil is bad.)

In any case, investigate the replacement part situation for
your computer. HP, for example, has the HP part store, and
you may be able to look there for an exact replacement fan.

While "standard" fans exist, manufacturers go out of their
way to use custom fans. Perhaps the fan they use is frameless,
and fits within the footprint of the copper heatsink. That makes
finding a replacement harder. You can't expect them to use
standard fans, since there isn't room inside the chassis for
such things to be installed. For a lot of other computing
equipment (desktops), I can go to my one good electronics
store in town, and expect to find nice replacement brushless
DC fans. The fan may not have a connector on the end, just
bare wires. By buying an associated crimp-on connector kit,
I can fit a three pin connector to the end, and replace a fan.
I did this a couple weeks ago, when I damaged my CPU cooling fan
while cleaning it. After cleaning, it would vibrate, so I had
to replace it. And using a connector kit, I was able to fit
a replacement solution. I would not expect doing this for
the laptop to be nearly as easy -- unless an exact replacement
part is available from someone. Since some laptop repair places
want $200 to "just look at it", if it was my laptop I'd be interested
in just fitting the fan myself. It all depends on how complicated
the disassembly procedure is, as to how practical that would be.

This is an example of a 40mm standard fan, with plastic frame.
I buy ones like this, to replace worn out fans in my external
hard drive enclosures. The one in a laptop is more likely to
be a "blower" design, with a side discharge from the fan body
rather than up and down flow.!BkY8iBgB2k~$(KGrHqUH-EEEs+GEi5!uBL(UqvZ(4!~~_3.JPG

You can see a couple of the blower types on this laptop. You'll
notice here, they didn't even use identical fans, but chose to
use different fans for each side. It looks to me like the CPU
cooler is on the right, and the GPU (graphics) cooler is on the


First  |  Prev  | 
Pages: 1 2 3
Prev: MSCONFIG Start Menu
Next: How to back up system???