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Vintage Audio (record players, hi-fi etc) Amplifiers, speakers, gramophones and other audio equipment. |
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18th Sep 2019, 11:32 am | #1 |
Dekatron
Join Date: Apr 2005
Location: North Wales, UK.
Posts: 6,884
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Dual Turntable motor fault.
Hi
I thought I'd eventually have a look at my old Dual 505 turntable which stopped working years ago. After replacing the microswitch (O/C) and the RIFA capacitors, the motor trembles but doesn't turn. Both coils measure around 1.8k and it spins freely. Motors aren't my strong point - is there anything I can do? |
18th Sep 2019, 9:19 pm | #2 |
Diode
Join Date: Sep 2019
Location: Manchester, UK.
Posts: 7
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Re: Dual Turntable motor fault.
replacing the capacitors usually sorts the motor,
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18th Sep 2019, 9:52 pm | #3 |
Dekatron
Join Date: Feb 2007
Location: Leominster, Herefordshire, UK.
Posts: 16,528
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Re: Dual Turntable motor fault.
Does it spin up if you "kickstart" it?
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18th Sep 2019, 11:51 pm | #4 |
Moderator
Join Date: Feb 2006
Location: Wembley, Middlesex
Posts: 7,219
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Re: Dual Turntable motor fault.
He's replaced the capacitors. See post #1
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19th Sep 2019, 11:08 am | #5 |
Dekatron
Join Date: Feb 2007
Location: Leominster, Herefordshire, UK.
Posts: 16,528
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Re: Dual Turntable motor fault.
You might have a shorted turn on one of the motor windings which wouldn't show up on a resistance check. Try inductance checks or a "ring" test if you can do them.
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....__________ ....|____||__|__\_____ .=.| _---\__|__|_---_|. .........O..Chris....O |
19th Sep 2019, 12:18 pm | #6 |
Dekatron
Join Date: Apr 2005
Location: North Wales, UK.
Posts: 6,884
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Re: Dual Turntable motor fault.
The reason I got it out of its slumber is that another identical turntable has come in for a simple repair. So I think a bit of swapping is in order!
Yo answer your question, it stubbornly sits there trembling. |
19th Sep 2019, 12:42 pm | #7 |
Dekatron
Join Date: Jul 2009
Location: Sleaford, Lincs. UK.
Posts: 7,639
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Re: Dual Turntable motor fault.
Have you re- checked your connections Glyn? Also did you use the right value caps and they're not actually snubbers, lastly make sure the caps you subbed are ok and not shorted or leaky. Short of that try a different value of cap.
Andy.
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Curiosity hasn't killed this cat...so far. |
19th Sep 2019, 1:12 pm | #8 |
Dekatron
Join Date: Apr 2005
Location: North Wales, UK.
Posts: 6,884
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Re: Dual Turntable motor fault.
Hmm.
When I put my motor in the good turntable it spins merrily BUT soon there's an unpleasant smell and the feed resistor (5k1, 5W W/W) is unhappy. This runs relatively cool in the customer's machine. Oddly, my board won't spin his motor at all! Confused at this point, but as it seems my motor is duff anyway there's not much point in going further. |
19th Sep 2019, 1:16 pm | #9 |
Heptode
Join Date: Oct 2007
Location: Southampton, Hampshire, UK.
Posts: 816
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Re: Dual Turntable motor fault.
It sounds like you have motor troubles but, as an aside, I always replace all the components on any of these that I service. The resistor runs hot and eventally the coating burns off and it stinks the whole time, plus one of the capacitors has a tendency to explode when it gets old!
A complete kit of compoenents is available on a "well known auction website" for only £9 which makes it a no-brainer in my book. |
19th Sep 2019, 5:18 pm | #10 |
Heptode
Join Date: Feb 2008
Location: Leven, Fife, Scotland
Posts: 823
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Re: Dual Turntable motor fault.
Hi Glyn, I have a scrap 505 which I believe the motor is ok. You are welcome to try it foc. Just let me know. Norman
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20th Sep 2019, 1:31 pm | #11 |
Dekatron
Join Date: Apr 2005
Location: North Wales, UK.
Posts: 6,884
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Re: Dual Turntable motor fault.
That's very kind of you, Norman, I'd appreciate that as I'd already invested in the capacitors, a stylus and belt before I realised it was the motor.
I'll send you my details via PM. |