IBM Engineers

From: Tony Duell <ard_at_p850ug1.demon.co.uk>
Date: Thu Apr 8 18:18:46 2004

> > On which planet have you been living for the last 20 years????
> >
> > I've never met a field servoid who had any sort of clue whatsoever about
> > the operation and troubelshooting of computers -- they just replace
> > seemingly random parts until the fault goes away. Certainly I've never
> > seen oue use a multimeter, let alone a 'scope...
>
> Heh. I've been stuck in the deal. I used to be one of three Macintosh
> field service engineers at Arizona State University.

You are _not_ a field servoid!

Yes, there are people who know how to fix computers. Many of them are on
this list, others are on another private mailing list that I frequent.
None of them are field servoids :-). Let me see if I can explain the
difference :

Field servoids :
-- Replace random parts until the problem appears to go away


Real computer repairers :
-- Use a 'scope, multimeter, logic analyster, etc to actually find the
cause of the fault
-- Are not happy replacing a part unless they can show that was the cause
of the fauly
-- Regard schematics, microcode source listings, firmware source
listings, databooks, etc as light bedtime reading. [1]
-- Write the service manual if none exists [2]
-- Make special tools and test boards, etc as appropriate [3]

[1] What, you mean you don't have a pile of service manuals by your bed :-)

[2] This was certainly done with the HP9100, 9810, and 9830...

[3] How else do you get the pullers to repair the card readers in the
9100 and 9810?

All of [1]. [2]. [3] apply to at least one person on this list :-). I
believe, BTW, that I am more of a 'Real Computer Repairer' than a 'Field
Servoid', but I'll let others be the judge of that.

>
> We used to *really* fix things, and I'm sure Apple would have been really
> upset if they knew that we used to really fix things, because it cost them a

I doubt very much if Apple would approve of what I did to my Mac+
(repaired it to component level), if IBM would approve of what I did to
this PC/AT (it's got extra chips and kludge-wires soldered to the
motherboard), or if HP would approve of what I do to 9100s and 98x0s.
Still, it's not for them to approve :-)

> lot of lost revenue in parts. I used to carry a multimeter around with me,
> so there. (;

When I go to HPCC meetings I carry a multimeter and a logicdart. So there ^2
:-) :-) :-)

>
> > I was once taught that the really good troubleshooter is the guy who
> > makes some measurements, thinks _a lot_ about the problem, and then
> > replacees exactly one part, and the machine works again for 10 more
> > years. I am not that good!
>
> Rules me out as well. I have to tell you, I'm self taught at all of this.

FWIW, I am entirely self-taught. I have never had one official lesson or
course in electronics or computing. I have no electronics or computing
qualifications at all.

IMHO self-taught people are often the best. They _want_ to know something
so they make darn sure they understand it properly. They don't give up
until they do...

> This a hobby that got out of hand. My favorite comment I ever got from a
> customer was, "we like you because you don't make stuff up. If you don't
> know the answer, you tell us."

There is nothing wrong with not knowing something. Heck, I know very
little, and am quite happy to admit it. There is also nothing wrong with
making mistakes. I'll admit to that too. If you claim to have never made
a mistake you're either a liar or have never done anything. Of course you
try to be careful when working on an irreplaceable machine (like an
HP95C, and yes, I have repaired one of those, and no it's not mine), or
when working with an irreplacable disk or tape. But yes, I'll even admit
to have occasionally corrupted the only known copy of something while
trying to back it up, and then having to spend a good few days undoing
the mess I made.

-tony
Received on Thu Apr 08 2004 - 18:18:46 BST