Music Hall mmf-7 spins faster


I have a Music Hall mmf-7 turntable (EAR 834P phono preamp) and it spins faster than normal. I bought a new motor and a new belt from Roy Hall, but it didn't change a thing. I borrowed my friends' motor (he has an mmf-7.1): no change... I even bought a Pro-Ject Speed Box (on Roy Hall's advice): it still spins faster. My cartridge is a Sumiko Blackbird. I really don't know what much else to do: any ideas? Did someone run into this problem?

I am desperate.
lrmellon
I did try that already, Almarg; thank you. It does spin closer than what it should, but still not at the correct speed. Without the Speed Box II, it's definitely too fast.

I also tried the other AC adapter: same result.

I unfortunately do not have a multimeter to measure those parameters.

Thanks again.
The recommendation for adding bearing oil is in the 7 manual also.Mobil 1 is the suggestion.Rega recommend 80/90 gear oil choice of oils could be important and if your turntable was in the attic for a couple of years,this is the first thing I would try.Make sure you coat the spindle and there is a coating of oil on the walls of the bearing recess and at the bottom of the well.Also play at least 1 album before you test and make adjustments.Warming the system up is crucial as well.
Thanks, Stefanl: I did read it in the manual. However, I am not sure what "main bearing" means. Where is it located: under (pardon my ignorance)? Please elaborate on the coating of the spindle.

As for warming up the system, it has been back out on top of my rack for more than 6 months now and I have played at leat 7 or 8 LP's so far, even with the atrocious (to my ears) speed problem, both with volume and mute.

I would appreciate any additional comments/advice (but I have yet to put electrical tape around the platter: it seems such a not so elegant trick).
The main 'bearing' is located at the centre of the platter.The spindle pokes up from it and you place the part of a record with the hole in it,through it,to hold the record in place.You take the belt and platter off and take the thing that pokes up out of it's hole.You now have a hole that is empty in the middle of the turntable,that you put oil into.Coat the long metal piece(spindle)that moves in the hole (bearing)with oil as is reasonable for moving parts and place some oil in the hole (bearing) also.The tape trick may not be needed if you oil properly,but the tweak works and that is what is needed.
Thanks again, Stefanl. Now, I get it for sure (what I thought I understood is certain now). I will oil both the spindle and the main bearing with Mobil 1 (with teflon). I'll let you know what my results are.