IBM 5155 analogue display fault

[Tony Duell]

> You would advocate physically marring a board as "reversible" since you
> could "solder a piece of wire over the break", but someone swapping screws
> is permanently altering a machine's make-up?
> 
> Please tell me you're joking.

No I am not joking...

A PCB cut and repair is (a) generally a useful modification (either to 
trace a fault, or to improve the machine in some way, and then to go back 
to the original configuration). And (b) it's bleeding obvious what's been 
done. 

It is _not_ obvious that the original screws were, say, Bristol Spline 
head if they've been replaced with Pozidriv or whatever. 

Now, if the machine was assembled with fasteners that were genuinely 
impossible to get the right tool to remove, or if it was pop-riveted 
together, or something, then I would agree it would be sensible to 
replace said fasteners with something more conventional and make a note 
to that effect if the machine was rare/significant. That's what I would 
claim to be a useful modification. 

My moan from the start is that there is no good reason to replace the 
original Bristol Spline screws with anything else. Period. And if there's 
no good reason to change something, you don't change it.

When there is a good reason to change something, then I see no problem 
with changing it, provided you document the changes and attempt to make 
sure said documentation is preserved.

-tony