25 Jun
2012
25 Jun
'12
9:25 p.m.
> Nor mine. For that matter, Tony won't like
my answers, either :-)
On Mon, 25 Jun 2012, Tony Duell wrote:
Since you posted them publically, I think it is
reasonable for me to
reply to them, whether you like it or not :-).
I like it very much!
I was thinking about you with every sentence of my post. I was hoping
that you would join in, fully knowing that we would not agree on the
"cheap tools" aspect.
And that is soemthing else to be careful about. A
friend of mine was
nearely killed by a cheap mete. He measured the voltage of a maisn
socket, it showed 240V or so, so the meter was working/ He flipped the
breaker for what he thought was the right circuit, then measured the
voltage again. 0 or so. So he thought he had isoalted the circuit and
started to remove the socket. Alas the meter had taken that momemnt to
fail (range swithc trouble I think) and he's flipped the wrong breaker.
Result : He got the mains across him. Second result, he bought a good meter.
A few days ago, a friend was repairing a hot-tub (spa) controller. He was
pretty sure that he had 220V, but the cheap meter said 0. Then the probe
fell off of the end of its wire - so THAT'S why it read 0. A meter, good
or bad, can not be a substitute for common sense.
You are skipping over something vert important here.
More than a few things! I only intended it as a framework, to be expanded
into a more thorough introduction to how to get started.
Multimeters, and
voltmeters in genral, have 2 leads. The poiunt is that it makes no real
sense ot say 'the votlage here is 5V'. What you mean is 'the voltage here
is 5V _with respect to this point which I am calling ground'. Knowing
what point to take as the common 'ground' is often not obvious when you
are startign out.
I did mention that (in the next step), but these instructions need a LOT
more detail!
My list of simple hand tools for ocmputer repair is
quite long, and to be
fair you problaby don't need all of them. But I find I need screwdrives
from 1mm to about 8mm, Phillips and Pozidriv ones too. And Allen hex
tools, torx drivers, nutdrivers, etc. In some cases it does depend on
what you are sorkign on. If you stick to C64s, you will not need Bristol
Spline tools. If yoyu work on Flexowriters, or even IBM 5155s, you do.
I think that a set of screwdriver bits is a good start there. There are
better screwdrivers than the bit holders, BUT, that could encourage using
the wrong size when a simple bit change (with a larger selection) could
have been done. My father understood the difference between "plain" and
"phillips" screwdrivers, but he never did grasp why there was more than
one size of either! I was about 10 when I started collecting my own hand
tools. My current tools don't resemble my early ones.
Get some decent pliers and cutters. Over here expect
to pay \poudns 30.00
for each (!). You will use them a lot .
Kits are great at teaching you to solder, to identify
compoennts and to
put things together. They are less good at teaching electronics. I was
One reason why I hesitated about making specific recommendations!
STEP SEVEN:
Get all of the technical documents for all of the machines that you want
to work on, or are even just curious about
Easier said than done in soem cases
:-). I think one thing that Fred and I agree on (from
reading this ) is that
there is no short-cut to being able to repair computers. You _do_ need
to learn to use tools,. you do need ot learn how things should work, you
do need to learn basic (and more) electronics.
Sure there are 'stock fault lists'. Thigns
that tell you that if it
starts up with this sort of image on the monitor then you need ot change
that chip. 99% of the time they're rignt./ 1% of the time they are not.
And at that point, if all you have is the stock fault lsit, you are stuck.
They're great for "probabilistically" suggesting where to START looking,
but one still needs to master the tool usage, AND understand enough theory
to be able to confirm the suggested diagnosis.
But if you are doing it for yourself, if you want ot
fix that machine no
matter what, then you have to learn the 'real' methods of fault
diagnosis.
There is no substitute for learning logical processes