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When caps go bad (Was U4K problem)
To: CRTech <crtech@crtech.org>
Subject: When caps go bad (Was U4K problem)
From: Willie Barnett <wbradiolists@gmail.com>
Date: Fri, 25 May 2018 10:13:35 -0400
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In my other job, I do a LOT of cap replacement. A good 90% of the time, you can quickly ID them, as they physically change in very visible ways... bulging, color-change, leaking goo all over the board, etc.

Then you have those insidious ones... that don't change appearance one iota, no visible leakage, etc... but when you remove & test 'em, they have almost no capacitance! :o

Dollars to donuts, that's what's going on with that flaky U4K unit. HOPEFULLY, you can just replace some caps, and have it purring like a kitten, again. :)

Willie...

PS TO ALL: Have a great weekend and a peaceful Memorial Day! :)


On Mon, May 21, 2018 at 1:23 PM, Bill Hurne <billhurne@pilgrimradio.com> wrote:

I haven’t had one chatter, but did have one fail that was fixed by replacing a bad cap on the power supply board.   Those units are getting old enough to have caps go bad.   The cap I replaced was the largest one, 150 ufd, 400 VDC.   The bad cap was physically bulging, easy to identify without a cap tester.

 

Bill

 

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