Faulty Dual CS 410 turntable - Page 2 - UK Vintage Radio Repair and Restoration Discussion Forum

Ted Kendall · 16th Jan 2020, 10:22 am

Please don't be put off - we all started as novices, acquiring knowledge bit by bit, and even a cheap meter will give you a much better idea of what's going on.

Station X · 16th Jan 2020, 10:28 am

Indeed. I started off knowing nothing. Physics lessosn in school taught me basic electrical stuff like batteries, resistors, series circuits, parallel circuits, Volts, Amps, Watts, Ohms Law and power calculations.

Valve theory I had to teach myself from books borrowed from the library and magazines. It's much easier now that we have the internet where you can ask a complete stranger for advice.

WalterGibbons · 16th Jan 2020, 12:16 pm

Quote:

Originally Posted by Station X

Indeed. I started off knowing nothing. Physics lessosn in school taught me basic electrical stuff like batteries, resistors, series circuits, parallel circuits, Volts, Amps, Watts, Ohms Law and power calculations.

Valve theory I had to teach myself from books borrowed from the library and magazines. It's much easier now that we have the internet where you can ask a complete stranger for advice.

Physics at school taught me that some teachers should really not be teachers.

I have taught myself many things since, but science continues to baffle me. Not because it's "too hard" just that my brain is wired differently to yours. I could list many skills I believe I have that you don't, but I'm not sure what that would achieve.

I simply want to repair a turntable if I can.

Edward Huggins · 16th Jan 2020, 1:02 pm

At the risk of this going Off-Thread, have you yet checked the advice given in Post#7 for Polarity?

WalterGibbons · 16th Jan 2020, 1:08 pm

Quote:

Originally Posted by Edward Huggins

At the risk of this going Off-Thread, have you yet checked the advice given in Post#7 for Polarity?

I haven't actually had time to check anything yet.

ms660 · 16th Jan 2020, 1:26 pm

So far as I can make out the centre connection is +ve (positive) and the outer connection is -ve (negative)

The same as the power supply for the Dual CS415 which uses the same power supply as the CS410, the connections in schematic form can be seen at the end of the CS415 manual that can be downloaded from here:

https://elektrotanya.com/dual_cs415_.../download.html

Lawrence.

Station X · 16th Jan 2020, 1:26 pm

Quote:

Originally Posted by Edward Huggins

At the risk of this going Off-Thread, have you yet checked the advice given in Post#7 for Polarity?

I think that's irrelevant at this stage Edward. The OP needs to test the existing PSU for voltage first.

Only if the existing PSU is faulty will he need to consider the polarity of a new one.

GeoffK · 16th Jan 2020, 6:21 pm

A small filament 12 V bulb could be used instead of a volt-meter. If it lights reasonably brightly the power supply is working. A 12Volt 2 Watt bulb as used in older Christmas tree lights would do.

WalterGibbons · 16th Jan 2020, 7:53 pm

Quote:

Originally Posted by GeoffK

A small filament 12 V bulb could be used instead of a volt-meter. If it lights reasonably brightly the power supply is working. A 12Volt 2 Watt bulb as used in older Christmas tree lights would do.

Really? I actually have a couple of them! How exactly would I perform this?

Ted Kendall · 16th Jan 2020, 8:39 pm

Depends on how dextrous you're feeling, but one way is to pinch the metal collar of the bulb to the sleeve of the connector with finger and thumb and put a piece of wire (an unbent paper clip would do) into the centre part and touch it against the bulb tip. Needs some dexterity to avoid shorting the supply, but it should be good enough to indicate output or no.

snowman_al · 17th Jan 2020, 8:13 am

Quote:

Originally Posted by GeoffK

A small filament 12 V bulb could be used instead of a volt-meter. If it lights reasonably brightly the power supply is working. A 12Volt 2 Watt bulb as used in older Christmas tree lights would do.

Please do not try this with your power supply.
The picture shows it has only a 20mA rating. A 12 volt 2 Watt bulb will draw 166mA.
Assuming it is working: If it has short circuit protection it will shut down (and not light the bulb), if it does not you could damage it... Apart from the chances of shorting it trying to connect it to the bulb.

Maybe some kind soul in Glasgow could loan you a meter (and show you how to use it)? Then Ebay has meters for a couple of pounds.

GeoffK · 17th Jan 2020, 12:50 pm

Yes I was looking at the wrong rating, the input VA. It seems a very puny power supply if it can only deliver 240milliWatts. This could be the problem, is the record deck pulling down the supply. In input of 1.5 VA and output of 0.24W not very efficient.

WalterGibbons · 17th Jan 2020, 1:52 pm

Quote:

Originally Posted by snowman_al

Please do not try this with your power supply.

I sort of decided not to try this anyway - lack of skills with proper equipment equates to a disaster waiting to happen when I start using paper clips and fairy lights!

WalterGibbons · 17th Jan 2020, 1:53 pm

Quote:

Originally Posted by GeoffK

Yes I was looking at the wrong rating, the input VA. It seems a very puny power supply if it can only deliver 240milliWatts. This could be the problem, is the record deck pulling down the supply. In input of 1.5 VA and output of 0.24W not very efficient.

The turntable worked perfectly for 30+ years with this power supply and it's manufactured, or at least supplied, by Dual. So I can only assume that it's adequate for the job.

GeoffK · 17th Jan 2020, 5:26 pm

If the power supply is faulty, as only 20mA at 12 V is required this could easily be achieved with 8 1.5 V AA or AAA cells wired in series i.e. plus to minus to make a battery of 12 V (note it is only a battery when two or more cells are joined). It would need 2 battery boxes of 4 cells making 6V each and joined in series, plus to minus, so the output has a plus terminal on one box and minus terminal on the second box to connect to the record deck. Battery snap connecters then wire the boxes to the record deck.

GroovyG · 18th Jan 2020, 1:22 pm

It seems that all that's needed is for a member in Glasgow to step up and offer direct hands-on assistance to the OP. Could result in a life-long friendship(??) Is anyone up for that?

bikerhifinut · 18th Jan 2020, 1:56 pm

Quote:

Originally Posted by GroovyG

It seems that all that's needed is for a member in Glasgow to step up and offer direct hands-on assistance to the OP. Could result in a life-long friendship(??) Is anyone up for that?

Seconded, I get the feeling that once the OP has been shown the process he'll soon latch on.

A.

WalterGibbons · 20th Jan 2020, 1:41 pm

Quote:

Originally Posted by GeoffK

If the power supply is faulty, as only 20mA at 12 V is required this could easily be achieved with 8 1.5 V AA or AAA cells wired in series i.e. plus to minus to make a battery of 12 V (note it is only a battery when two or more cells are joined). It would need 2 battery boxes of 4 cells making 6V each and joined in series, plus to minus, so the output has a plus terminal on one box and minus terminal on the second box to connect to the record deck. Battery snap connecters then wire the boxes to the record deck.

I really wish this wasn't all double dutch to me - a battery powered TT sounds great, but to a guy who struggled with the concept of a paper clip and fairy light bulb, this might as well be rocket science.

WalterGibbons · 20th Jan 2020, 1:42 pm

Quote:

Originally Posted by bikerhifinut

Quote:

Originally Posted by GroovyG

It seems that all that's needed is for a member in Glasgow to step up and offer direct hands-on assistance to the OP. Could result in a life-long friendship(??) Is anyone up for that?

Seconded, I get the feeling that once the OP has been shown the process he'll soon latch on.

A.

Absolutely!

stuarth · 20th Jan 2020, 3:45 pm

The 20mA rating on the power supply doesn’t seem right. The Dual website lists many models, but the power is either 230V or 12V 150mA. 20mA seems more appropriate for a photo preamp than a drive motor. The CS410 is listed as 230V, but if your deck is 30 years old, it could be a different design with the same model number.

The 20mA written on the power supply may be a misprint and it’s actually more powerful than that. Is there any engraving on the deck where the power supply plugs in?

Have you had the Dual a long time, or have you recently acquired it? (I noticed that in your earlier thread on the Pioneer amp, you had an SP25). If you’ve recently acquired it, could the power supply have been swapped with another, or a mains lead been removed? The power supply might be just for an optional pre-amp.

Regards, Stuart

16th Jan 2020, 10:22 am	#21
Ted Kendall Dekatron Join Date: Jul 2008 Location: Kington, Herefordshire, UK. Posts: 3,670	Re: Faulty Dual turntable Please don't be put off - we all started as novices, acquiring knowledge bit by bit, and even a cheap meter will give you a much better idea of what's going on.

16th Jan 2020, 10:28 am	#22
Station X Moderator Join Date: Jan 2003 Location: Ipswich, Suffolk, IP4, UK. Posts: 21,288	Re: Faulty Dual turntable Indeed. I started off knowing nothing. Physics lessosn in school taught me basic electrical stuff like batteries, resistors, series circuits, parallel circuits, Volts, Amps, Watts, Ohms Law and power calculations. Valve theory I had to teach myself from books borrowed from the library and magazines. It's much easier now that we have the internet where you can ask a complete stranger for advice. __________________ Graham. Forum Moderator Reach for your meter before you reach for your soldering iron.

16th Jan 2020, 1:02 pm	#24
Edward Huggins Dekatron Join Date: Sep 2015 Location: Southwold, Suffolk, UK. Posts: 8,327	Re: Faulty Dual turntable At the risk of this going Off-Thread, have you yet checked the advice given in Post#7 for Polarity? __________________ Edward.

16th Jan 2020, 1:26 pm	#26
ms660 Dekatron Join Date: Apr 2011 Location: Cornwall, UK. Posts: 13,454	Re: Faulty Dual turntable So far as I can make out the centre connection is +ve (positive) and the outer connection is -ve (negative) The same as the power supply for the Dual CS415 which uses the same power supply as the CS410, the connections in schematic form can be seen at the end of the CS415 manual that can be downloaded from here: https://elektrotanya.com/dual_cs415_.../download.html Lawrence. Last edited by ms660; 16th Jan 2020 at 1:41 pm. Reason: Additional info + link

16th Jan 2020, 6:21 pm	#28
GeoffK Heptode Join Date: Mar 2016 Location: Essex, UK. Posts: 602	Re: Faulty Dual turntable A small filament 12 V bulb could be used instead of a volt-meter. If it lights reasonably brightly the power supply is working. A 12Volt 2 Watt bulb as used in older Christmas tree lights would do. __________________ *Geoff*

16th Jan 2020, 8:39 pm	#30
Ted Kendall Dekatron Join Date: Jul 2008 Location: Kington, Herefordshire, UK. Posts: 3,670	Re: Faulty Dual turntable Depends on how dextrous you're feeling, but one way is to pinch the metal collar of the bulb to the sleeve of the connector with finger and thumb and put a piece of wire (an unbent paper clip would do) into the centre part and touch it against the bulb tip. Needs some dexterity to avoid shorting the supply, but it should be good enough to indicate output or no.

17th Jan 2020, 12:50 pm	#32
GeoffK Heptode Join Date: Mar 2016 Location: Essex, UK. Posts: 602	Re: Faulty Dual turntable Yes I was looking at the wrong rating, the input VA. It seems a very puny power supply if it can only deliver 240milliWatts. This could be the problem, is the record deck pulling down the supply. In input of 1.5 VA and output of 0.24W not very efficient. __________________ *Geoff*

17th Jan 2020, 5:26 pm	#35
GeoffK Heptode Join Date: Mar 2016 Location: Essex, UK. Posts: 602	Re: Faulty Dual turntable If the power supply is faulty, as only 20mA at 12 V is required this could easily be achieved with 8 1.5 V AA or AAA cells wired in series i.e. plus to minus to make a battery of 12 V (note it is only a battery when two or more cells are joined). It would need 2 battery boxes of 4 cells making 6V each and joined in series, plus to minus, so the output has a plus terminal on one box and minus terminal on the second box to connect to the record deck. Battery snap connecters then wire the boxes to the record deck. __________________ *Geoff*

18th Jan 2020, 1:22 pm	#36
GroovyG Pentode Join Date: Nov 2015 Location: Witney, Oxfordshire, UK. Posts: 229	Re: Faulty Dual turntable It seems that all that's needed is for a member in Glasgow to step up and offer direct hands-on assistance to the OP. Could result in a life-long friendship(??) Is anyone up for that?

20th Jan 2020, 3:45 pm	#40
stuarth Heptode Join Date: Feb 2010 Location: Heysham, Lancashire, UK. Posts: 668	Re: Faulty Dual turntable The 20mA rating on the power supply doesn’t seem right. The Dual website lists many models, but the power is either 230V or 12V 150mA. 20mA seems more appropriate for a photo preamp than a drive motor. The CS410 is listed as 230V, but if your deck is 30 years old, it could be a different design with the same model number. The 20mA written on the power supply may be a misprint and it’s actually more powerful than that. Is there any engraving on the deck where the power supply plugs in? Have you had the Dual a long time, or have you recently acquired it? (I noticed that in your earlier thread on the Pioneer amp, you had an SP25). If you’ve recently acquired it, could the power supply have been swapped with another, or a mains lead been removed? The power supply might be just for an optional pre-amp. Regards, Stuart