Should you correct production mistakes?
ard at p850ug1.demon.co.uk
Thu Aug 26 13:32:24 CDT 2010
> Eric writes:
> > Tony Duell wrote:
> >> I could trivially desolder the IC, straighten the pin, and solder it
> >> properly. But should I? What would others do?
> > Had we found any problem analogous to that in the PDP-1 restoration,
> > where the machine operated correctly despite a manufacturing defect, I'm
> > sure we would have had a debate on whether to fix it. I think my own
> > opinion in that case would be that we should leave it alone, but tag the
> > module (paper tag attached with a short loop of string) and document the
> > issue in the system logbook.
> > For something that isn't considered a museum artifact, I'd be more
> > inclined to fix it.
> Whatever happened to "if it ain't broke, don't fix it"?
I've always wondered where that idiotic saying came from. Do you wait
until your car engine seizes before you change the oil? Do you wait for
the timing belt to break voalves to hit pistons before you replace said
belt? Or do you do mainenance?
If you saw a tiny leak fro ma brake sylincer on your car would you carry
ion driving (it's working fine, I csan stop the car), or would you check
that cylidner, replace seals, etc before it failed totally and you ran
In the case of classic computers, I always do a visual inspection
inside, chgeck the PSU on dummy load, etc before poweing it up for real.
More than once that's saved me having to replace a lot of parts.
> The ability of a robust assembly and QA process to result in working systems,
> despite small manufacturing errors, is remarkable. If the board passed QC
> and was released into the wild and is still working decades later, that
> is a fact worth noting but I see zero reason to correct it. I don't doubt
> anyone's soldering skill but there is still a small and nonzero chance
> that any attempted "fix" would result in hassles.
I can;t think of anythign that could happen when repairing this which
would not itself be curable. If I wreck the IC, well 74LS221s are not
that rare. Alas it wouldn't have an 1820-xxxx numberm but it would work.
If I managed to lift traces off the PCB, I could repair them. It's not a
critical cirucit for layout.
More information about the cctech