Thorens TD 150 MKI question

[mdc701]

Hello all,

I’m being offered a cosmetically great Thorens TD 150 MkI with some issues, mainly that the power and speed knob doesn’t function. Thus you’ll need to plug and unplug the unit in order to use it. My question is, should this be an easy fix? I’m thinking the speed problem is due to a worn out belt. It’s the power issue that i’m more concerned with. The deck is being sold to me as is roughly for around $200. It also has the TP-13 arm, which i will probably replace anyway with something that has a tonearm lifter.

Any help and suggestions would be greatly appreciated…thanks!

Mario

 

[timmy.timmy]

A new belt will correct the speed change issue for a while. In the mean time you can put the old in some boiled water off the gas and put it out after 5 or 10 minutes to let it dry. Fit it back on and see if now the lift guide pulls it up the pulley with the platter upside down on the sub-platter so that you can see how it works. Mind you a isopropyl clean of the pulley and sub platter side is also welcome.

If you can't switch the motor off without unplugging it, unplug the turntable from the mains. Take the bottom plate off to access inside the turntable. Before putting the turntable upright or upside down always take off the platter then take of the headshell and tie the tonearm to it's rest. Lay the turntable upside down with the sub-platter on the platter laying flat and upright on a table under good light.

You'll see that the on/off switch is activated by the speed button by either pulling it up or down. Hopefully you should be able to see if the switch is mechanically working or not. Then tell us how it all went to help you further if ever. God willing not Now there are other crucial maintenances to do before enjoying it playing music like a re-lube of the bearing, a suspension and stylus check...

 

[mdc701]

A new belt will correct the speed change issue for a while. In the mean time you can put the old in some boiled water off the gas and put it out after 5 or 10 minutes to let it dry. Fit it back on and see if now the lift guide pulls it up the pulley with the platter upside down on the sub-platter so that you can see how it works. Mind you a isopropyl clean of the pulley and sub platter side is also welcome.

If you can't switch the motor off without unplugging it, unplug the turntable from the mains. Take the bottom plate off to access inside the turntable. Before putting the turntable upright or upside down always take off the platter then take of the headshell and tie the tonearm to it's rest. Lay the turntable upside down with the sub-platter on the platter laying flat and upright on a table under good light.

You'll see that the on/off switch is activated by the speed button by either pulling it up or down. Hopefully you should be able to see if the switch is mechanically working or not. Then tell us how it all went to help you further if ever. God willing not Now there are other crucial maintenances to do before enjoying it playing music like a re-lube of the bearing, a suspension and stylus check...

Thanks for replying! The TT is with me now, and when i plugged it, i needed to give the platter a little nudge and when measured with an iphone app, the speed at 33 was more or less ok. However, when switched to 45 the speed remained at 33 ish. Could this still be a belt problem?

As mentioned earlier, pulling the speed button up doesn’t stop the motor from spinning. I’ll try to follow what you suggested and post back here.

 

[mdc701]

@timmy.timmy

So I did as you suggested. The switch seems to be working fine…i mean it clicks up and down like how it should. So does this mean that the switch is defective? Is there a way to replace this?

 

[timmy.timmy]

@timmy.timmy

So I did as you suggested. The switch seems to be working fine…i mean it clicks up and down like how it should. So does this mean that the switch is defective? Is there a way to replace this?

Yo ! 'mdc701' sorry but you have to take off the bottom plate and do all as I told you in order to see (not only hear) what is happening from below with the switch. I know it may sound very "military" but there's only one way to check that.

As for the nudge to get it going do the belt boil thing, the isopropyl clean and if you feel ready a suspension check with the turntable leveled and 4 to 7 mm gap between the top plate and the platte and a little bounce. Once all set 'GO' !

 

[mdc701]

 

[mdc701]

Here are some pics for reference. It seems that this has been repaired before as the wires have been spliced together. Am not sure now if this is the original switch.

Edit: I’ve been told that everything is stock…sorry.

 

[timmy.timmy]

Here are some pics for reference. It seems that this has been repaired before as the wires have been spliced together. Am not sure now if this is the original switch.

With the wires have been spliced together what do you mean exactly ? I can't see anything odd about the cables nor the switch just from looking at your pictures.

And by the look of it it's still the original switch there. And it does 'click' as you mentioned, so could it be faulty by now ? How is the rest of the inner power wiring ?

 

[mdc701]

With the wires have been spliced together what do you mean exactly ? I can't see anything odd about the cables nor the switch just from looking at your pictures.

And by the look of it it's still the original switch there. And it does 'click' as you mentioned, so could it be faulty by now ? How is the rest of the inner power wiring ?

The wires have these plastic looking caps so i thought someone had spliced them together. But i saw the TD 150 manual and the wires were indeed like that originally. So they’ve never been touched.

Anyway, yes the switch still clicks. It may be faulty due to age? You think it could be replaced by a similar switch? The other wiring seems ok. I’ll post a pic later when I get the chance. Thanks for your help Timmy. I really appreciate it!

 

[mdc701]

The yellow capacitor near the switch is a bit sticky. Could that be the culprit?

 

[timmy.timmy]

No. I was wondering if the switch was not 'bypassed' by any chance as it seemed not to be operating anymore to "cut" the power.

As if the previous owner got the loud 'POP' out of the speakers at one time when he/she switched-on the turntable. It can happen.

And instead of replacing the faulty 'spark' resistor (yellow) went on to bypass the switch to "solve" that issue. But apparently not.

Or maybe not. That because one will have to have a scheme of the actual power circuitry here in order to tell if that is the case or not.

From here with the pictures & time it would be possible to do that and verify if that is the case. But roughly judging on a peek it's not.

 

[mdc701]

Thanks. So i guess a faulty switch would be the most reasonable reason for now? I’ll try to replace the switch and see how it goes. Was thinking since I plan to change the plinth anyway, maybe i can just put a new power switch on the side of the plinth and just use the 33/45 knob to control the speed. Or maybe just the replace the toggle switch and see if i can get it to work properly. Thanks a lot for all your inputs Timmy!

 

[timmy.timmy]

Thanks. So i guess a faulty switch would be the most reasonable reason for now? I’ll try to replace the switch and see how it goes. Was thinking since I plan to change the plinth anyway, maybe i can just put a new power switch on the side of the plinth and just use the 33/45 knob to control the speed. Or maybe just the replace the toggle switch and see if i can get it to work properly. Thanks a lot for all your inputs Timmy!

Yeah. A broken connection would mean no power. A leaking capacitor would make the motor inconstant. There's only the switch left. Not that it does not want to turn ON but it can't be turned OFF.
Am a twaeker too so go ahead there. As for a switch I would attempt first a fix. Then a similar replacement or else an outside cord or plug switch rather than an addition like the Linn's or Ariston's...

 

[ZebraBlvd]

The speed change issue is a problem with the belt getting moved up or down on the pulley attached to the motor. This could be either a belt, pulley or mechanical problem. I would recommend that you go to a site that deals with all Thorens. I use it as my my bible for referencing problems, upgrades, etc. Link below.

https://www.theanalogdept.com/


Here is a pic of my 150 I spent a year on upgrading, a labor of love.

 

[mdc701]

The speed change issue is a problem with the belt getting moved up or down on the pulley attached to the motor. This could be either a belt, pulley or mechanical problem. I would recommend that you go to a site that deals with all Thorens. I use it as my my bible for referencing problems, upgrades, etc. Link below.

https://www.theanalogdept.com/


Here is a pic of my 150 I spent a year on upgrading, a labor of love.

Thanks for your insights. That’s a sweet looking TD 150! I see you replaced the speed/power knob. Is that a toggle switch? How do you power up and change from 33 to 45?

 

[mdc701]

Just to update, the toggle switch is working fine. I had an electrician check it. So that leaves the yellow capacitor as a possible cause for the switch’s malfunction. I ordered some new capacitors. Let’s see how it goes.

 

[timmy.timmy]

To replace the old capacitors before they wear out is never wasted. Apparently I was wrong assuming that the sticky 'yellow' thing was the 'spark' resistor. According to the schematic this is the 0.1uF capacitor. The long light grey thing opposite to it is the spark capacitor. Anyway good to hear that your switch is out of cause. You can always check if your circuitry is also correctly connected.

 

[mdc701]

Thanks Timmy. I really hope replacing that capacitor fixes the problem. I’ll get around doing it over the weekend hopefully.

Btw, I removed the belt and noticed that the motor needs to be helped initially before it starts spinning. Does this mean the motor needs to be lubricated or something?

 

[timmy.timmy]

Thanks Timmy. I really hope replacing that capacitor fixes the problem. I’ll get around doing it over the weekend hopefully.

Btw, I removed the belt and noticed that the motor needs to be helped initially before it starts spinning. Does this mean the motor needs to be lubricated or something?

A little drop of lube in the motor's bearing from above and below is always welcome every now and then. Now I bet that motor start will be solved with the new capacitors. What about the spark resistor ? Are you going to give it a new one too ? Or not ?

Still I can't get my head around the idea that the switch is OK and yet you can't switch 'OFF' the power ! How can that be the capacitor's fault ? BTW be careful while handling off your old capacitors as they are still full of juice ! Could that explain you can't turn if off ?

 

[mdc701]

A little drop of lube in the motor's bearing from above and below is always welcome every now and then. Now I bet that motor start will be solved with the new capacitors. What about the spark resistor ? Are you going to give it a new one too ? Or not ?

Still I can't get my head around the idea that the switch is OK and yet you can't switch 'OFF' the power ! How can that be the capacitor's fault ? BTW be careful while handling off your old capacitors as they are still full of juice ! Could that explain you can't turn if off ?

Am thinking the same, but that seems to be the most logical solution? Anyway, we’ll soon find out. Also, based on the schematics you sent, I’m wondering why my unit has the resistor when it’s in fact a 117v/60hz unit? It should be the same as the second figure right, the one without the resistor?