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#1
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Possible but highly unlikely.
To troubleshoot this (and I have had to troubleshoot similar issues before) disconnect the B+ rail and filter cap connection to your the 5U4 (remove all load from it). If it stops arcing you have confirmed the B+ rail has a short or severe overload. If it continues to arc with no load then the socket may have a short or the transformer may be supplying too high an AC voltage. Assuming the arcing stopped reconnect the first filter cap then reconnect small parts of the B+ 1 at a time (not all at once) the first one to cause arcing is your short, and you'll have to pick it over with a fine tooth comb to find the root cause. I've fought a few B+ shorts. Sometimes they are obvious if you look everywhere, sometimes they are hidden... Case in point: a 40s zenith chassis with only a couple rubber wires in seemingly good shape...the single rubber wire feeding the eye tube had one dry patch of insulation that had disintegrated right at the eyelet where it passed through the chassis, and was invisibly shorting to chassis there... just because you can't see a problem, and have replaced the likely suspects doesn't mean the problem isn't there.
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Tom C. Zenith: The quality stays in EVEN after the name falls off! What I want. --> http://www.videokarma.org/showpost.p...62&postcount=4 |
#2
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All the electrolytic caps should be replaced, dry or not. Over time the dielectric breaks down just like the paper caps do. That 500 mfd cap can be replaced with a 470 mfd. Voltage rating can be higher, say a modern 25v shouldn't be much bigger than the original.
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#3
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Would a 470 MFD 6.3 VDC electrolytic cap work as a replacement for this capacitor? Also there's a 100 MFD 150 VDC capacitor that was a replacement at some point for C7 which was a 100 MFD 25 VDC electrolytic capacitor that must of failed at some point in time. The strange thing is that when they hooked up the negative lead on that capacitor instead of using using the floating ground rail on one of the tube sockets or something they hooked the negative lead of that electrolytic to the chassis, which might also be causing some of my issues, C7 by the way according to the Sam's is the Vertical Output Tube Cathode Bypass Capacitor. Last edited by vortalexfan; 09-10-2019 at 05:58 PM. |
#4
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As for the B+ Voltage Rail and where it connects to the rectifier tube and how to test it where is that point on the Rectifier tube socket? |
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