Re: mutt/exim [solved] - how to rewrite sender-name
On Sat, Jan 16, 1988 at 12:25:38AM +0100, Dieter Schoppitsch wrote:
> On Tue, Dec 17, 2002 at 05:14:25AM +0000, Pigeon wrote:
> > > I didn't find the bios-battery to replace it.
> >
> > You don't have to replace it with the exact same one. As long as you
> > get the voltage and the polarity right, you can use any
> > non-rechargeable lithium battery that will fit in the space. Voltage
> > and polarity are usually pretty clearly marked, except on coin cells
> > (which are all 3V and the button bit is negative, case positive).
> >
> Actually I didn't find any battery (except my accupack) when I took
> apart my laptop.
Sorry, I thought you meant you couldn't find a replacement on sale
anywhere.
> * Where does such a pile sit in a laptop (usually)?
Anywhere they can fit it in :-)
> * Could it be some kind of capacitor?
Possibly, yes. Imagine getting an ordinary electrolytic capacitor,
standing it on end and hitting it with a hammer. The short, fat thing
you end up with looks much like the capacitor sometimes used for this
purpose. It's usually hard to read the markings because of the short
fat shape, but the value is usually a farad or so. (They get such huge
capacitance in such a tiny space by using the electrode potential as a
dielectric, which I think is a really neat idea.) If you find one of
these, try probing its voltage every hour or so with a *digital*
voltmeter and see if it's losing charge.
Another possibility, which is similarly shaped but somewhat larger, is
a small rechargeable battery soldered into the PCB. It's usually
obvious when this has failed from all the corrosion where it has
leaked, but still worth checking with a voltmeter if there is no leak.
A third possibility is that the clock chip has a battery built in,
which is a f**g stupid idea but that didn't stop them doing it. This
would probably be a 28-pin DIL chip with a fat package. If it's in a
socket, give thanks. If it's soldered in, there's not much you can do.
You can't unsolder them with a normal soldering iron; you need a big
thing which can heat all 28 pins at once, and there's still a big risk
of damaging the PCB.
(Don't get confused with the BIOS ROM, which may be in a similar
package, but not fat, and usually with the BIOS manufacturer's sticker
on it.)
Pigeon
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