3 Feb
2017
3 Feb
'17
12:38 p.m.
On 2017-02-03 3:47 PM, Tony Duell wrote:
On Fri, Feb 3, 2017 at 7:04 PM, dwight <dkelvey at
hotmail.com> wrote:
...And if you don't have a schematic, you ring out the connections and
draw your own...
Paul.
I think Tony's statement about the key thing
to know about
trouble shouting is to know what it should be doing.
If you don't know that, no scope or logic analyzer with help much.
Yes. I once
explained faultfinding in this way. The technical manual,
schematics, microcode listings, etc should tell you what the device
should be doing. The instruments tell you what it is doing, you need
test instruments becuase you can't directly 'see' electrical signals.
You then have to compare the two and work out what could cause
the problem.
There is no magic box that you plug into a computer and it tells
you 'U5 is faulty'. At least not in general.
As I have said before, the most important piece of test gear is a
brain.
-tony