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Forum Index : Electronics : Kingsley Record Player

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Dinosaur

Guru

Joined: 12/08/2011
Location: Australia
Posts: 303
Posted: 02:40am 20 Oct 2020
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Hi All

After retirement have got involved with the local museum.
Someone brought in a:Kingsley Radio Model KP205 with a circuit board CB1.3.
Basically just a turn table with Volume/On/Off knob and a speed selector.
Does not include a radio.

It works but the volume is low.
First observation is that an 1000mF electrolytic looks a bit bulged on one end.
So will replace that and see.
Volume pot seems OK.

However can't seem to find a circuit for the board.
It is not the older Valve amplifier, but has transistors.
Someone has obviously modified it by fitting a heatsink that looks homemade.

Google doesn't bring up any hits.
Would anyone here have or know where to get a circuit for this.

Any help appreciated.

Regards
Regards
Hervey Bay Qld.
 
Grogster

Admin Group

Joined: 31/12/2012
Location: New Zealand
Posts: 9029
Posted: 03:30am 20 Oct 2020
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DEFINITELY replace the bulging cap.  If that does not fix it, you probably/possibly have dried-up audio coupling caps.  Depending on age and type of caps used, they can dry up internally over the decades, and then don't couple the audio signal as they used to.  Finding a circuit might be tricky.  I know a few chums in the trade, I will see if they recognize it.  I've never even heard of that brand though, but that might simply be cos they never sold them in NZ perhaps.

Also, check that the speaker is not simply faulty or partly blown.  I have seen all sorts of fun there with speakers over my time in the trade, including voice-coils that come unstuck from the cone and therefore do not produce the volume they should.  Try fitting a temporary speaker in place of the old one(or in parallel if you think the amp can handle the lower impedance) and see if you get more volume from your test speaker.  That might be all there is wrong with it.

HCSD forums are also extremely useful - full of service techs.  Someone over there might be able to help if it gets more complicated then that.  Click on "HCSD Forums" on the menu at the left, and follow your nose from there.

Good luck.  
Smoke makes things work. When the smoke gets out, it stops!
 
Dinosaur

Guru

Joined: 12/08/2011
Location: Australia
Posts: 303
Posted: 03:57am 20 Oct 2020
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Hi All

Many thanks for your reply Grogster.
That link is definitely worth book marking.

Regards
Regards
Hervey Bay Qld.
 
CaptainBoing

Guru

Joined: 07/09/2016
Location: United Kingdom
Posts: 1983
Posted: 07:18am 20 Oct 2020
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  Grogster said  DEFINITELY replace the bulging cap.


+1 on that, I would go further and replace *all* electrolytic caps.

I have found them to be problematic in refurbs even when they don't outwardly show any signs. I watch lots of refurb vids on utoob (Marco Reps is a favourite) and they systematically replace any caps as it can prevent diagnostics later.

good luck
 
Grogster

Admin Group

Joined: 31/12/2012
Location: New Zealand
Posts: 9029
Posted: 06:52am 21 Oct 2020
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Back when I used to do a lot of VCR repairs(they're all gone now!), there was a very common National/Panasonic VCR whose PSU would always cook its 85'C caps dry as a bone, then the PSU would not run anymore, so the VCR would not power-up.

I've lost count of how many re-cap kits I used back in those days - basically replaced every single electro cap in the PSU, both hot and cold side, with 105'C rated caps.

It was a very common problem, and a very easy fix for countless National/Panasonic VCR units, so caps can certainly be a source of problems - perhaps more so then you would give a simple cap the credit for.

To the best of my recollection, re-capping those VCR PSU's always fixed them.  I don't ever recall re-capping one and it NOT bringing the VCR back to life again.

....ahhhhhhh, memories of servicing past.....
Smoke makes things work. When the smoke gets out, it stops!
 
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