<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html;charset=ISO-8859-1">
<title></title>
</head>
<body text="#000000" bgcolor="#ffffff">
I should probably mention one other factor - <br>
<br>
Unfortunately, I don't have an extender card for the Lexicon either.
(Think how easy this would all be with a service manual and an extender
card....)<br>
<br>
Of course, those aren't available from Lexicon either.<br>
<br>
I'm thinking that if I can't nail ths soon I might have to make an
extender card - might not be a bad thing to have anyway.<br>
<br>
So, is it normal for the 74s163 to drop the resistance between +V and G
by about 10 ohms?<br>
<br>
Also, I'm a big believer in replacing just about any tantalum of this
vintage with an electrolytic. I know this is a controversial topic,
but if we're not talking about the audio path, what does everyone think?<br>
<br>
Tim<br>
<br>
<br>
Ken Stone wrote:<br>
<blockquote type="cite"
cite="mid200504200538.j3K5cET09373@duckula.hotkey.net.au">
<pre wrap="">Replacing the Tantulums is always a step in the right direction. Use low ESR
electros if you can. Old tants are a common source of failure.
A quick "test" for misbehaving chips is to feel the temperature they are
running at. If one is unusually hot, it may be in a state of partial or
complete failure.
If any capacitor is part of a reset circuit, replace it.
Ken
</pre>
<blockquote type="cite">
<pre wrap="">The board has eight 4.7uF and two 22uF tantalums spread around between
+5V and ground. I put a meter on it while it was out of the mainframe
and found that between +V and Ground I'm only reading about 170 ohms of
resistance. This seems awfully low to me. Perhaps a leaky tantalum
that's not completely shorted out? Or is this possibly correct?
</pre>
</blockquote>
<pre wrap=""><!---->_______________________________________________________________________
Ken Stone <a class="moz-txt-link-abbreviated" href="mailto:sasami@hotkey.net.au">sasami@hotkey.net.au</a> or <a class="moz-txt-link-abbreviated" href="mailto:sasami@cgs.synth.net">sasami@cgs.synth.net</a>
Modular Synth PCBs for sale <a class="moz-txt-link-rfc2396E" href="http://www.blaze.net.au/~sasami/synth/"><http://www.blaze.net.au/~sasami/synth/></a>
Australian Miniature Horses & Ponies <a class="moz-txt-link-rfc2396E" href="http://www.blaze.net.au/~sasami/"><http://www.blaze.net.au/~sasami/></a>
</pre>
</blockquote>
</body>
</html>