Pioneer speed issues.

[karma67]

for a while now the pioneer has been having speed issues,once adjusted it will either slow down or speed up a little and you have to keep adjusting the pitch controls.its not extreme although you can hear it when it does it, after an hour or so it seems to stabilize.
i've been off work today with a cold and got bored so i decided to investigate :grin:



here's a shot with the secondary metal plinth removed.



the ply plinth removed,i like the fact that its all contained in one unit.



here's one with the motor cover removed.







now ive done the obvious thing and given the pitch adjusters a good spray of contact cleaner and its still the same,im worried that some of the capacitors are too old and that might lead to something terminal failing so should i replace the capacitors as a preventative measure??

[Audio Al]

Have you looked at the bearing ?

[struth]

Usual culprits are the 2 youve mentioned.. a resistor could too

[Yomanze]

Bearing will be fine, the two culprits are the speed pots needing to be replaced (more than just a spray), as well as old caps coming up to temperature over time & altering the parameters i.e. the speed changes. Resistors will be fine.

[karma67]

cheers,can the speed pots be bought new or is it a second hand jobby?

[Beobloke]

No, DO NOT go replacing capacitors at random. There's a chance it will make no difference and you could make things worse. There is a current thread on another forum where a poster re-capped his perfectly working Technics direct drive because he read on the internet that it's the 'thing to do', and now it doesn't run properly!

Checking and cleaning the pots is a good idea but if that doesn't work then take it to someone who can check it out properly. I can give you a name for this if you need it.

[karma67]

cheers adam,dont worry i wont go changing caps.
ive taken the backs off the speed pots and given them a good spray with cleaner,it appears to have done the trick,all im getting now is very slight fluctuation,not having owned a DD before i dont know if this normal or if it should be total stationary??



[IMG]IMG_1189[1] by , on Flickr[/IMG]

[mik_rik]

Had problems with speed control on my Pioneer Pl630,doing similar to the complaint on your's.Cleaned the pots as you have ,turned out it was the speed change switch which needed a good spray of Servisol.Exellent articles on same problem by a very experienced engineer on Audiokarma site[recommends spraying then working the switch 100 times or so] Hope this is of some help Mick

[Beobloke]

They really don't need spraying 100 times!

Jamie, as well as the two pots that you use to set the speed from the top of the deck, there will be two more internal speed adjustment pots on the actual PCB inside - you can see them on your first picture. You should also give these a squirt of Servisol or similar and turn them across their full adjustment range a few times to work it in. Do remember, of course, to note their original positions and put them back there afterwards!

And to answer your question, there should be no fluctuation - if should be steady. If it's not a quartz lock, you might find the speed will alter slightly after half an hour or so's running (they usually speed up slightly) but if you then correct it at this point, it should not change again.

[karma67]

Thanks I will do the others tonight after work, its already much better so hopefully the other 2 pots will sort it