I built a TubeHobby clock in 2006. A couple years ago it quit working and kept blowing the fuse. During troubleshooting, I found that the 170 power supply measured 24 ohms to ground. I removed C6 and the 24 ohm resistance went away. C6 checked good, so I reinstalled it and the clock worked. I don’t know where the low resistance came from. Tin whisker? Solder splash? Circuit board manufacturing defect? The clock is still working 2 years later.
> On Sep 1, 2016, at 12:51 PM, MichaelB <[email protected]> wrote: > > Had another TubeHobby clock start blowing fuses the other day and I know > others on this forum have had similar issues. I have 4 of these muxed clocks > and 2 that drive IN-18’s, the others use smaller tubes like the Z566M and the > Z574M and have been fine. However, I have had issues now with both of the > IN-18 clocks where the 1st blew C6 (see attached PS schematic) and now this > one has eaten (shorted, or darn near, measures .3ohms) the 270uf inductor. > Replaced it and the clock has run fine now for 3 days, so its fixed for now. > Not sure what it is about this clock's power supply driving IN-18’s and so > wondered if others have noticed this problem and what a long term cure might > be? Included the power supply schematic for review. > > -- > You received this message because you are subscribed to the Google Groups > "neonixie-l" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected] > <mailto:[email protected]>. > To post to this group, send email to [email protected] > <mailto:[email protected]>. > To view this discussion on the web, visit > https://groups.google.com/d/msgid/neonixie-l/ff7e483e-96e6-4172-b9b8-0bae8a326a2b%40googlegroups.com > > <https://groups.google.com/d/msgid/neonixie-l/ff7e483e-96e6-4172-b9b8-0bae8a326a2b%40googlegroups.com?utm_medium=email&utm_source=footer>. > For more options, visit https://groups.google.com/d/optout > <https://groups.google.com/d/optout>. > <TubeHobby NCV2.1_manual+Schem. 21.pdf> -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send an email to [email protected]. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/C9A34EF8-BEFC-4BDE-9D8F-DEB1ADEDBA84%40pobox.com. For more options, visit https://groups.google.com/d/optout.
