Dansette conquest turntable motor help

[Smt02tof]

Originally Posted by Cobaltblue

I found this on the net at livinginthepast-audioweb

Most of the resistor values can be read the Cap is not in the pictures which helps.

The board is the other way around so to compare it to Lawrence's list you need to look right to left

Cheers

Mike T

Thanks for this I have saved the image to my phone and will print off in A4

[Smt02tof]

Hi all further to my last post, I have now changed all the resistors for the correct values, so all the caps have been replaced and resistors but I still have exactly the same problem , the valve lights up and the record plays, absolutely no hum at all but the sound is still distorted.
The circuit board is in tact, I have checked continuity and all is good, the rectifier is the original but I have a replacement if required, I’m just at a loss to what the issue could be, I even changed the cartridge again just in case it had developed a fault, not being an expert at electronics and only having a cheap meter this player may have to be stored for now, thanks everyone for you help, I have learnt a great deal from all your comments.

[Station X]

Can you post a picture of the reworked PCB please. It might give a clue as to what the problem is.

[Smt02tof]

Graham thanks for your interest, I have attached some images of the finished circuit board,I have used a meter to check all continuity, you can see that I have had to repair some of the circuit board due to damage, you would think it’s something I have done because the sound was not distorted before I replaced the resistors, although there was significant hum, the hum has now completely gone.
Thanks for your help

[Richardgr]

Voltages on all the valve pins would be useful, taken clockwise starting after the large gap when looking under the tube,

Connect the meter lead to ground, and measure DC. Also record the AC voltage on pins 4 and5.

[Smt02tof]

Here are some extra images

[Richardgr]

Looking at that PCB, I think you might need plan B, replace or rebuild. There is a responsibility that goes along with tinkering with high voltage equipment, that might be used by others. That PCB does not look like it is serviceable anymore, and could be a trap for the unwary.

[Edward Huggins]

Yes, the track looks damaged/weakened and are those 2 resistors on the LHS meant to be wired in series? I think there's been much physical disturbance to the PCB by far too many (and perhaps uneccesary) component changes....
On these basic amplifiers sometimes all that is needed is a replacement coupling cap and the triode anode load resistor. Was it really necessary to rush to change all those passive components?

[Smt02tof]

Thanks richard I will test the voltages ASAP and let you know, where would I get a new PCB ?

[Smt02tof]

Originally Posted by Edward Huggins

Yes, the track looks damaged/weakened and are those 2 resistors on the LHS meant to be wired in series? I think there's been much physical disturbance to the PCB by far too many (and perhaps uneccesary) component changes....
On these basic amplifiers sometimes all that is needed is a replacement coupling cap and the triode anode load resistor. Was it really necessary to rush to change all those passive components?

Edward, my initial idea was to rebuild the record player to as new condition, in hindsight I could well have left some of the components as they were, but we live and learn, if I had bought the player today I certainly set about things in a different way
Thanks anyway for all your assistance, my knowledge although still limited is increasing, the turntable runs like a dream now it’s just the amp

[Smt02tof]

Originally Posted by Edward Huggins

Yes, the track looks damaged/weakened and are those 2 resistors on the LHS meant to be wired in series? I think there's been much physical disturbance to the PCB by far too many (and perhaps uneccesary) component changes....
On these basic amplifiers sometimes all that is needed is a replacement coupling cap and the triode anode load resistor. Was it really necessary to rush to change all those passive components?

Edward I wired 2 resistors together to get the correct 18 ohm resistance

[Smt02tof]

Originally Posted by Richardgr

Voltages on all the valve pins would be useful, taken clockwise starting after the large gap when looking under the tube,

Connect the meter lead to ground, and measure DC. Also record the AC voltage on pins 4 and5.

Richard voltages are below
1- 650 ac 335 DC
2 0 ac 0 dc
3 788 ac 366 dc
4 818 ac 371dc
5 0 ac 0 dc
6 both 0
7 again 0
8 0/0
9 also both 0
Hope this helps

[ms660]

I would measure them again.....meter set to measure AC for pin 4 and pin 5, meter set to measure DC for the rest of the pins.

Lawrence.

[Richardgr]

Originally Posted by Smt02tof

... where would I get a new PCB ?

The amp is quite simple, so maybe someone knows of a tagboard layout? The ECL82 is not an easy tube to wire up due to the proximity of a lot of wires for the two different tube types in the envelope.

Do you have any photos of the front and rear from before you started work on it?

If we can find the exact schematic, then one option would be to disconnect the PCB, leave the socket attached, but clean off the remains of the traces that were damaged, then insert the correct components (confirmed from the schematic) through the holes, and use the leads on the components as substitute traces on the other side.

Maybe we could look at a picture of the layout prior to soldering so that we could confirm it looks ok?

Once you have the schematic, you can ring the shared connections at every point where components are joined, so you can see exactly what connects to what and how many connections there should be.

You are going to have to be Miss Marple, however!

[Smt02tof]

Originally Posted by ms660

I would measure them again.....meter set to measure AC for pin 4 and pin 5, meter set to measure DC for the rest of the pins.

Lawrence.

Sorry Laurence
4 - 1 showing but crackles when I touch it
5 - 7.2v AC

[G8UWM-MildMartin]

I suspect pin 4 is actually pin 6 (pentode anode) and you have counted the pins incorrectly.

[Smt02tof]

Originally Posted by Richardgr

The amp is quite simple, so maybe someone knows of a tagboard layout? The ECL82 is not an easy tube to wire up due to the proximity of a lot of wires for the two different tube types in the envelope.

Do you have any photos of the front and rear from before you started work on it?

If we can find the exact schematic, then one option would be to disconnect the PCB, leave the socket attached, but clean off the remains of the traces that were damaged, then insert the correct components (confirmed from the schematic) through the holes, and use the leads on the components as substitute traces on the other side.

Maybe we could look at a picture of the layout prior to soldering so that we could confirm it looks ok?

Once you have the schematic, you can ring the shared connections at every point where components are joined, so you can see exactly what connects to what and how many connections there should be.

You are going to have to be Miss Marple, however!

Richard
I do have the schematic for the amp, it may be better to try and get myself a replacement board
But thanks I will certainly take everything on board

[Edward Huggins]

You are highly unlikely to get a replacement PCB other than complete donor amplifier.
Best to "hard-wire, re-wire", as explained above using the long wires from the new components to join each together.

[Smt02tof]

Originally Posted by G8UWM-MildMartin

I suspect pin 4 is actually pin 6 (pentode anode) and you have counted the pins incorrectly.

I am sure it’s 4 if we are counting from the big gap clockwise but strange thing is when I test on the 500v scale I get 800,
But it’s 1 on 200 scale please see attached images, hopefully I am using the tester correctly

[snowman_al]

A couple of thing are evident...
The pin numbering is clockwise from underneath the valve holder. That is pin 6 in reality.
You have your meter on AC volts. That is what the V~ symbol indicates. You need the V--- setting. The 1 reading on that location of the meter tells you it is out of range.