This problem is covered in my cave.
The motor could simply be binding. If the motor is winding up too tight then the controller will kill power to protect it. That is exactly what the controller is suposed to do.
This is very likely the case if you can unwind it a bit by hand and then they run normally. If you haven't tried a couple turns by hand before turning them on then do that first.
If they are binding...
Take the cover off the gears.
Put a drop of oil in/on each bearing in there. There are 4. Two on each shaft. You don't usually need to worry about the fifth bearing under the knob.
I use Valvoline's Synpower spray oil for this type of job. WD40 and most other sprays won't work or won't work for long. "3 in 1" or Gun oil can probably also be used.
You need a product made to lubricate. Penetrating oils won't do for this.
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No good ever came from dark and spooky. Norville "Shaggy" RogersThe Ogre's Fiero Cave (It's also at the top of every forum page...)