how to troubleshoot? Not all of us have trustfunds!

[Paul Perry]

At 10:08 PM 13/01/01 -0800, RFAHL wrote:

>Also, couldn't you use an audio cable as a probe between the circuit and an
>audio amp (with a DC blocking cap for protection), using your ears instead
>of your eyes?   
>
This is very good advice indeed.
Back in the days of discrete radios, and even today for valve amps,
some people would permanently set up a 'test' one with links between
the setions, so you could send & receive signals to the unit being 
fixed. 
I'm suprised how often it is possible to 'diagnose' a circuit without
ANY test gear at all, when people on the lists ask what 'might be wrong'.
The best advice i ever saw, went along the line that the 'broken' gear
you are working on isn't really 'broken', it is just that it has somehow
been transformed into some OTHER circuit. And, you have to find what 
THIS circuit is. The reverse logic here often leads to insight. 

http://polly.phys.msu.su/~zeld/oscill.html
was mentioned on the guitar fx bbd as a real time audio scope for an
IBM soundcard. I havn't tried it myself.

paul perry melbourne australia