[sdiy] a little OT, but...

[Magnus Danielson]

Dear Bob,

Bob Devries wrote:
> Does anyone here have, or have links to, a schematic of an OP-AMP 
> tester that's not too involved?
>
> I'd like to:
> (a) do an initial GO/NO GO test, and then
> (b) do some basic parameter tests
>
> I've gotten involved with a local community radio station as 
> electronics tech, and the electronics of the two studios are primarily 
> based on LM833 dual OP-Amps.
My favorite trick to test if an op-amp operating in linear mode is 
broken or not is to use a multi-meter and check if the DC voltage 
between + and - input. It should be 0 mV or there abouts. I've nailed 
most of the broken op-amps by that simple measure. The main resons when 
this does not work as a diagnosis is when it is operating in 
non-linear/comparator-mode or that due to other circuit errors (such as 
short or transistor burned into a short) the output is forced to some 
other voltage level.

Cheers,
Magnus