I have had a BeoCenter 7700 for about three years, and when I bought it, I replaced all the belts.  Just in the last few months, the speed changes from 33 to 45 in the middle of a record.   If I press 33 it changes back and stays there.  This happens about three or four times a week, while I use the turntable about 28 - 34 hours a week.  What could be the cause of this? 

Tim
 

Hello Tim

It seem that the automatic speed selector need to be realigned, the speed is selected by the disk adaptor position.

The unit must to be opened to realign the selector. 

If you need other info let me know

ciao ciao (aka bye bye)

Thanks - that makes sense.  However, I have no idea how to get inside this one, all I have is the original owner manual.  Can you give a any tips on how this is done?  

Thanks,

Tim
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            

Hello Tim

Speed change could be done operating on the two pushbutton (33-45) OR by a reed relay placed on the lower side of the turntable (The dark side of the TT ) 

To check this reed relay you have to open the unit (The Beo), and control the contact; could be some mech problem or there could be a cap defective, so you have to change it.

It is not so difficult but is better to let a technician check inside, if you are enough skilled to open the unit let me know (I don't know if skilled is the right word so read as " if you normally open a Beocenter 7700 once a week") :)

Let us know,

ciao ciao 

Hello

Have you solved the problem? 

I haven't tackled the problem yet.  The system belongs to a friend, and he realized his MMC4 is sounding rather dull, so I've loaned him another turntable for now.  I've download the service manual and we plan to open it up and make adjustments/change the belt, etc., when he's ready to buy a new cartridge.  So I think we're headed in the right direction - thanks for your help!

 
Tim