Dansette Prince

[simpsons]

Hi Gary

All sounds good.

One thing, unless you already have one, get a desolder sucker. They costs £3.39 on eBay. A small reel of desolder wick won't go amiss either as the wires soldered to the volume control, from the pictures I've seen, are wrapped around the terminals as is standard practice. Pulling them free with lots of solder splattering the printed circuit and other components will be a nightmare. Well it had been for me before I knew better!

Should there be enough "spare" then it might be possible to cut and rework the connection but be cautious if using a "Stanley" blade to trim screened cable. It is very easy to cut through the outer sheath into the screen and the same goes for the inner core.

Good luck and let the forum know how you are getting on.

Chris

[Minster97]

Will do thank you.

[Minster97]

A little update, the potentiometer shafts on the replacements are far too short. Dansette seemed to know that when I phoned them. There is supposed to be a new batch arriving so any potential buyers should enquire as to the correct length. I think the new ones will be made too long so you cut to size.

Gary

[Minster97]

My new volume on off pot has just arrived. I took the old one off noting where everything went with photos. Two brown and two blue wires easy to get to. The three tags underneath were more tricky. Peel off the adhesive cover. I desoldered them using wick to soak up the solder. New pot fitted, turned on red light on but absolute silence, not the faintest hum from anywhere. I fiddled all afternoon and decided to put the old one back and still silence.

I have obviously done something stupid but what? I can only think it must be something related to the circuit board which I know absolutely nothing about. All three pot tags sent through a round hole ring and were soldered to that.

Any ideas please?

Gary

[Edward Huggins]

So the red pilot light comes on but nothing else. It sounds like there is no mains supply getting through to the UY85 anode. Have you dislodged this valve? Is there power to the motor? Are the valve heaters lighting up?

[Sideband]

Originally Posted by Edward Huggins

So the red pilot light comes on but nothing else. It sounds like there is no mains supply getting through to the UY85 anode. Have you dislodged this valve? Is there power to the motor? Are the valve heaters lighting up?

This is the transistorised version....no rectifier valve!

[Minster97]

Sorry if this is duplicate reply. Deck motor works and can’t see anything dislodged. No valve.

[Minster97]

I think the problem is that I have damaged the PCB trace .This has to be repaired.
I have looked on the net and get different solutions.
This was my first time and lesson learned.
I don’t know how easy it will be to fix.
I am happy to take it to a professional if my attempts at repair can make things worse
Any advice please?
Gary

[julie_m]

The best place to start would be to take some good, clear pictures of the PCB, with the camera held perfectly parallel to the board so there is no trapezoidal distortion (aka "keystoning"); at least overviews of each side of the whole board, and maybe close-ups of any suspected damage. Someone should be able to advise from there.

[Minster97]

Thank you.Photo.The old pot is back not soldered as you can see.I notice that I have I think damaged the red track ,it is certainly missing on the right.

[julie_m]

That certainly looks damaged! The copper pad seems to have come away from the board during desoldering.

You will have to scrape away some of the solder mask coating from somewhere further along the track to reveal the copper underneath, and solder a length of wire from there to the potentiometer pin.

[Minster97]

Thank you,will have a go!

[Sideband]

You should treat yourself to some desolder braid. Have a look on eBay. Once you have used it you will wonder how you managed without it....

[Minster97]

I did buy some braid but probably not adept enough.Lesson learned.

[julie_m]

While you're at it, get yourself a flux pen. Modern solder is flux-cored, and new desolder braid has flux in it, but it's amazing what a difference a bit of extra flux makes. Especially if you're using lead-free solder.

[simpsons]

Two issues spring to mind in de-soldering the volume control from the photo.

First, the adhesive left behind when the insulation was peeled back to expose the pc connection. It looks as if the joints are contaminated. Should the adhesive not be cleaned off before trying to remove the solder, using de solder braid, it would mean that mean that it would soon be contaminated making the job take much longer. Hence the track problem. It will also make re-soldering problematic.

Second, not with standing the contamination, the reason why I recommended using a de-solder sucker not braid was from experience. It remove solder very quickly minimizing damage to the track. The braid to be used on the wired connection to the volume control after using the de-soldering sucker.

Should the old soldered joint not melt then try "re-soldering the connection." Flux from the fresh solder will mix with the old making the task much easier.

Chris

[Minster97]

Thank you. I cleaned all the old adhesive off using solvent which didn’t damage anything else. I have resoldered and checked for continuity along the orange/red track which there is. What I mean is that I got a resistance reading ie not open circuit. I have checked that I wired the pot exactly as before and still absolute silence, red light is on.
It was working OK before I changed the pot (crackly), no loose connections.
I am really stuck as to what could have happened?

[Michael Maurice]

I got to look at this a few days ago. The volume control had been very crudely fitted using some 10A twin and earth wire.

Fortunately he had another pot which I fitted with much thinner wire going to the pot.

After that we switched on, but the amplifier only comes to life whilst the player is playing. The customer didn't realise this.