Superlead blowing mains fuse

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lp1987x
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Superlead blowing mains fuse

Post by lp1987x » Sun Oct 02, 2016 1:15 pm

I have a '74 Superlead that keeps blowing the 4 amp mains fuse. With no power tubes installed, the fuse does not blow. In checking voltages, I'm seeing 2.8 volts ac at the heaters. However, I'm only seeing -5.8 volts dc on pins 5. Does anyone have any idea what might be causing this odd reading and if this could be the issue?
Craig

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Re: Superlead blowing mains fuse

Post by Roe » Sun Oct 02, 2016 3:48 pm

measure AC and DC voltage in the bias circuit
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neikeel
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Re: Superlead blowing mains fuse

Post by neikeel » Tue Oct 04, 2016 12:14 pm

Already have a thread on this working through the problem in the logical way on plexi palace Marshall section :thumbsup:
Neil

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