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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>In my repairs I see a lot of screwy 4000 series that died. They never quite fail but they start acting strange. I have a couple of photos on <a href="https://modularsynthesis.com/modules/tips/tips.htm">https://modularsynthesis.com/modules/tips/tips.htm</a><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>One is a CD4011 where the logic low output is 3.72V. Another was 4520 where it stopped dividing and simply output pulses the same width as the clock. I would suspect some of these are age deterioration although I have no proof. Some could be static damage which doesn’t necessarily show up immediately.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>At the vintageTEK museum we get donations including parts. I’m surprised when people kept defective parts that were rejected. We get a tube of ICs that are marked reject. We got a bag of hundreds of knobs that weren’t drilled for a setscrew. Some of the rare parts I see on recent Buchla clone builds are getting worse and worse, like they were fallouts.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>I like the idea of characterizing these (but I’m not volunteering). Is the date code old? I would suspect damaged or marginal parts that never got taken out of circulation.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><br>Dave<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><div style='border:none;border-left:solid blue 1.5pt;padding:0in 0in 0in 4.0pt'><div><div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'> Synth-diy [mailto:synth-diy-bounces@synth-diy.org] <b>On Behalf Of </b>Mattias Rickardsson<br><b>Sent:</b> Wednesday, September 22, 2021 12:30 PM<br><b>To:</b> Mike Bryant<br><b>Cc:</b> Synth DIY<br><b>Subject:</b> Re: [sdiy] Issue with CD4024 Ripple Counter<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><div><div><div><div><p class=MsoNormal>Mike Bryant <<a href="mailto:mbryant@futurehorizons.com">mbryant@futurehorizons.com</a>> skrev:<o:p></o:p></p></div><blockquote style='border:none;border-left:solid #CCCCCC 1.0pt;padding:0in 0in 0in 6.0pt;margin-left:4.8pt;margin-right:0in'><div><div><div><p class=MsoNormal>I wonder if the CD4024 has an inverter on the input and both the faulty ones have blown the inverter by static, hence the signal just punches through unchanged and clocks on the wrong edge?<o:p></o:p></p></div></div></div></blockquote></div></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>Interesting idea. But:<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><div><blockquote style='border:none;border-left:solid #CCCCCC 1.0pt;padding:0in 0in 0in 6.0pt;margin-left:4.8pt;margin-right:0in'><div><div><div><div><p class=MsoNormal>David G Dixon via wrote:<o:p></o:p></p></div></div></div><div><p class=MsoNormal><span style='font-size:10.0pt'><br> clocks on both edges with switch.<o:p></o:p></span></p></div></div></blockquote></div></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>Hmm!<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>/mr<o:p></o:p></p></div></div></div></div></body></html>