Alarms

[Nigel Henry]

On Saturday 17 May 2008 17:14, Martin Laberge wrote:
> On Saturday 17 May 2008 06:47:48 Bill Vance wrote:
> > Howdy;
> >
> > I have a very annoying two tone alarm going off, right now.
> >
> > Its not going out over the sound card.  Any way to find out what's
> > going on, how turn it off, etc?  It goes away during shutdown but
> > returns shortly after reboot, without the slightest hint or clue as
> > to the cause.....:-(
> >
> > Bill
>
> I think this the OverHeat alarm, warning you to shutdown now
> or burn your system. on my machine, this shutdown the system
> after a few minutes if i dont do it.
>
> Check the fan of the CPU and be sure it is properly installed
> and it is clean. Or check the fan of the power supply,
> it may be full of dust.
> --
> Martin Laberge

I do remember getting the two tones a while back, and may well have been the 
bearings of the PSU fan on my not so expensive i-Friend machine ran out of 
oil, resulting in the fan stopping. thankfully the PSU has a thermal cutout, 
which just resulted in the machine shutting down abruptly.

At the time I was puzzled as to why the machine had shutdown, but taking the 
cover off, restarting it after a few minutes, and looking at the works, I saw 
that the PSU fan was a no-go. Sometime later after having stripped down the 
PSU, cleaned out all the dust from it, and having re-lubricated the bearing 
on the fan (using musical instrument oil, which is all I had at hand, and 
which had a hypodermic needle type applicator for the oil, and very usefull 
when applying oil to small moving parts) I re-installed the PSU, and prayed.

The machine has been running for between 18 months, and 2 years now, with no 
further problems.

It's always a good idea to get the dust out of the machine from time to time, 
and do this perhaps every 6 months. Machine with cover off in the back yard, 
vacuum cleaner on blow ( banging the hose a bit to get the vacuumed in dust 
out of it), then go for it. It's simply amazing how much dust builds up on 
fan blades, and gets pulled onto the CPU heatsink by it's fan, and certainly 
there's a whole bunch of dust comes out of the PSU unit.

I try to keep away from the optical drives, and the floppy drive, in case I 
should blow dust into them.

I did see mention that spinning the fans when doing this cleanout operation 
could cause the creation of electricity feeding back into the PSU. I'm not 
too sure about that. Servo's create a voltage when spun, but whether that 
applies to fans in the computer I don't know, and havn't had any problems 
myself.

I also thought of connecting a ground/earth connection to the machine, when 
doing the vacuum cleaner dust blowout, as I believe there can be some static 
electricity buildup from fast moving air. My ground lead wasn't long enough 
to reach the back yard, so hoped that there would be no problems. I did see 
suggested though to allow some minutes after blowing out all the dust, before 
rebooting the now dust free machine.

Anyway I have had no problems using the vacuum cleaner on blow on my machines, 
to clean them out.

I suppose there will be some feedback on my comments, but as it's the weekend 
I'm game for it.

Nigel.