10 Oct
2007
10 Oct
'07
6:22 a.m.
On Tuesday 09 October 2007 21:53:01 Tony Duell wrote:
<much snippage>
No, I'm working under the assumption that hardware works logically, when
it fails to work there's a good reason for it, and that before you can
claim to have repaired it you have to have found that reason.
Heh, I remember troubleshooting a PC that would work with a CD ROM
disconnected, but not with it connected - even if you left the IDE cable off
(actually it's long enough ago that it might have been a Mitsumi interface)
Guess what it was? The 'scope told me, the +12 rail was all over the place.
Once the second CD ROM was connected up, it swung wildly from 9v to 15v.
Why? Who knows? Who cares? Let's maybe try a bigger PSU than the dinky
130W one the case came with. Oh wow, look at that, it even runs at less than
fingerprint-removing temperature...
Look on the pavement the night before the bins are collected. I have a couple
of nice P3 1GHz desktops which I picked up like this. They may well have
been riddled with spyware and viruses, I don't know. The first thing I did
was flatten the drives and install Ubuntu.
One of them is now at a friend's Mum's house being a word processor and
internet thing, the other is in a different friend's recording studio being a
sampler.
I try to only use things I can repair or rebuild, but I appreciate that there
are some things that should just be considered a complete replaceable part.
I've repaired computer boards (the memory board for my PDP11, for one) and
I've repaired "sealed" ECUs in cars (the suspension ECU in Citro?n XMs, many
times). I *replaced* a ball joint, because it was 30 quid and I've got no
chance of making one, especially for that kind of money. I *replaced* a
serial controller card, 'cos it was a fiver and again I doubt I could build
one for that.
Gordon
And I said 'appear' above. Maybe the
motherboard is fine. Maybe it's a
marginal PSU that can't supply enough current for the 3 DIMMs. Did you
even chack the PSU votlages under load? Let alone ripple?
And again, you're working on the assumption that I am you, or that I
work like you, or that everyone should work like you. How am I inconveniencing myself? What do you think I
want to do that
could be done more easily by having a modern PC? (And remember I think
_you're_ inconveniencing yourself by not having electronic test gear and
learning how to use it)
You've said yourself that you don't have (easy) access to resources like
bitsavers.org, because some of the formats used require fairly modern PCs.
I'd find that pretty inconvenient.
ARGH! When are you going to understand that I
don't replace parts without
knowing what's failed and why!. I simply don't. I never will...
I must admit, I don't just replace bits without at least trying to guess why
they might have failed. Obviously if the cause of the failure is obvious,
it's not worth spending time on (most recent example being (sorry folks) one
of my cars, where it was "Let's see, why might these ball joints have 6mm of
play? Maybe because of 19 years of British roads?").
It's a lot less inconvenient to me to stick to
hardware I know, that I
understand, and that I can keep going to avoid any such problems.
Not keen on learning new stuff, then?
something
worth at best hundreds and probably in fact worth perhaps
the cost of a pint or a train ticket is not sensible pragmatism, it's
You also have to realise that not everybody knows people who give away
old PC hardawre. I don't, for example. not
commendable attention to detail, it's bl**dy daft. And to say "I
won't run it if I can't repair it" is dafter still!
I disgaree, but there you are...