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Sony CD/Radio wont's stay turned on...

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Nick de Smith

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Oct 12, 2015, 6:00:31 AM10/12/15
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Hi - I have an old-but-very-good-condition SOny CFD-44 rado/CD/Casstte player - been reliable for many years... Extremely well made unit - do NOT want to scrap it unless forced :)

Recently, every so often it won't stay turned-on - when it's off, you press the power button and the red power LED comes on for maybe 0.5 seconds - a very small "pop" from the loudspeakers, and it then turns off - normally, a light press on the power button and it stays on fine - the power button is a momentary-press push-button, not a latching switch, so its not that.

When its fine (90% of the time) it's an excellend radio cassette...

Bit puzzled as to where to go next...

Thanks

mako...@yahoo.com

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Oct 12, 2015, 10:12:35 AM10/12/15
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electolytic caps on the B+

Mark

Nick de Smith

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Oct 12, 2015, 1:27:50 PM10/12/15
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On Monday, 12 October 2015 15:12:35 UTC+1, mako...@yahoo.com wrote:
> electolytic caps on the B+
>
> Mark

Checked the main reservoir caps - 6800uF @ 25V - ESR was 0R2 @ 100Hz, seems pretty much ok...

Nick

M Philbrook

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Oct 12, 2015, 7:22:29 PM10/12/15
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In article <4c73540d-1249-4ab8...@googlegroups.com>,
ni...@desmith.net says...
sounds like a cap reforming..

Jamie

Phil Allison

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Oct 13, 2015, 12:56:06 AM10/13/15
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Nick de Smith wrote:
>
>
> Checked the main reservoir caps - 6800uF @ 25V
> - ESR was 0R2 @ 100Hz, seems pretty much ok...
>
>

** That figure would be the cap's impedance at 100Hz.

The ESR value is much lower, maybe 0.02 ohms.

Most ESR testers use a frequency between 20kHz and 100kHz, where the impedance and ESR values are near the same.


.... Phil

NewsDemon

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Oct 21, 2015, 6:11:16 AM10/21/15
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"M Philbrook" <jamie_...@charter.net> wrote in message
news:MPG.30860c64b...@news.eternal-september.org...
Nope. Bad connection somewhere. Solder connection, problem with a connector,
etc.

Mark Z.

NewsDemon

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Oct 21, 2015, 6:11:17 AM10/21/15
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"M Philbrook" <jamie_...@charter.net> wrote in message
news:MPG.30860c64b...@news.eternal-september.org...

NewsDemon

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Oct 21, 2015, 6:11:17 AM10/21/15
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"M Philbrook" <jamie_...@charter.net> wrote in message
news:MPG.30860c64b...@news.eternal-september.org...

Mark Zacharias

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Oct 22, 2015, 7:56:52 AM10/22/15
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"NewsDemon" <mark_za...@sbcglobal.net> wrote in message
news:4xJVx.91206$Bl2....@fx27.iad...
Sorry for multiple postings. Problem with new server.

mz

pf...@aol.com

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Oct 22, 2015, 8:28:24 AM10/22/15
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First, the disclaimer: I am not familiar with that unit.

Now the two alternate diagnoses:
a) If a capacitance-start (solid-state contact-start switch), replace the capacitors as already noted. It might not be a bad idea in any case. And don't stop with the main filters, look to any caps in the starting circuit. Such switches may also operate a small reed relay or solid-state relay. If a reed relay, it may be worn out and not holding. If an SS relay, see caps, above and elsewhere.

b) If a mechanical switch, look for dirty contacts, a slipped or worn-through contact or similar. Can you jumper the switch and have it operate normally?

As I remember, and, for the record, that little pacific-rim audio equipment that I own is all Sony or Yamaha, Sony does like solid-state switches as they are much easier to manage with remote control, so I expect that this will devolve to a capacitor problem.

Best of luck with it.

Peter Wieck
Melrose Park, PA
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