Seeking Xceed Color30 card

Tony Duell ard at p850ug1.demon.co.uk
Thu Apr 10 16:46:49 CDT 2008


> The book the poster on the other related thread is probably thinking about
> is Larry Pina's "Macintosh Repair and Upgrade Secrets", which Tony
> probably disapproves of.  :-)   Pina discusses and recommends replacement
> of components based on the items which, in his experience, most often lead
> to certain symptoms.   He does not discuss doing an actual probe and
> diagnosis to determine the failed component, which is why I good naturedly
> refer to Tony's disapproval.

And you'd be right :-). It's what I call 'lucky dip servicing'. It may be 
useful if you have lots of similar machines to repair, or if you run a 
repair shop, or similar. Perhaps 95% of the time the book will get it 
right, or rather the most common failure is what's gone wrong with the 
machine on the bench.

But that other 5% of the time, it'll be wrong. And becuase the book 
doesn't explain the reasoning behind the diagnosis it gives, it won't 
help you find the real fault, even if the real cause is a component in 
the same part of the circuit as the one you've just replaced based on 
said book.

I must admit that just abotu every repairer uses a bit of this 'lucky dip 
method'. There'll be common causes for problems that he'll check first. 
But a _good_ repairer will know how to continue if none of those are the 
problem.

Incidentally, had the original machine been a Mac+, I could possily have 
helped, as I've worked on those and have a fair idea how the analogue 
board works. But IIRC the SE/30 is very different, and I don't have one 
of those to look at.


-tony



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