Re: Asteroids DAC question

From: Clay Cowgill <c.cowgill_at_comcast.net>
Date: Fri Sep 09 2005 - 19:56:34 EDT

> Assuming you've already traced the output, and know the signal is corrupt
on
> the output of the DAC (It doesn't go bad at the op-amp) . .
>
> Could you piggyback a second DAC on top, let all pins touch except the
> output, and compare the two outputs ?

That probably won't work 'cause (IIRC) the 561 is a current output DAC, so
you really wouldn't see anything at the output since there's no resistor to
convert the current into a voltage you could compare...

That having been said, I've seldom seen DAC failures so while it does happen
I'd say it's usually something after the DAC 9 times out of ten.

One other quick check would just be to use a logic probe/scope/etc. to look
at the inputs to the DAC just to make sure you don't have a stuck input
line, that could make a DAC look "bad" as well...

-Clay

---------------------------------------------------------------------------
** Unsubscribe, subscribe, or view the archives at http://www.vectorlist.org
** Please direct other questions, comments, or problems to chris@westnet.com
Received on Fri Sep 9 19:56:11 2005

This archive was generated by hypermail 2.1.8 : Sun Sep 11 2005 - 20:50:01 EDT