Linn LP12/Lingo start-up/speed problems

I have a Linn LP12/Lingo 2 that has started to display issues on start-up; firstly it takes a long time to get up to speed and motor/sub-chassis/arm-board shake during start-up and secondly the motor/Lingo will just die during play and the record will grind to a halt. I was hoping it might be the motor as I could change this my self but Linn thinks it is a problem with the Lingo which requires a visit to the dealer; has anyone encountered a similar issue?

I bought the Linn in 1991 with a Valhalla power supply but upgraded to the Lingo a few years latter. The motor is the older version with a cap/spring/ball bearing on the bottom of the motor shaft. I have read that these items can be dispensed with the Lingo power supply; any comments anyone?

I had those symptoms when my Valhalla board died. You could look into the DC motor kits out there for a few hundred bucks for the LP12. They get good feedback but I haven’t heard one.
I'd be very surprised if the problem is mechanical, rather than electronic. I had a Thorens TD-125 Mk.2 whose electronics created the same "motorboating".
I  agree to start with removing cap, spring and ball before doing anything. It will do exactly what you discribe. It's easy to do, just do it slow because spring can through ball and you will be on your hands and knees looking for it like I did. Soon as I did it problem solved. Mine did it with Pink Triangle pink link power supply not lingo.

I removed the cap/spring/ball from the bottom of the motor as suggested by 'paulcreed'. Everything seems to work perfectly now, would not have thought that doing this would have made any difference. As a consequence I have vertical 'play' in the motor shaft, can move it up and down by about 3mm. I read somewhere that a hole should be drilled in the bottom of the cap, a nylon nut would then be glued on the inside of the cap above the hole, and then cap cap stuck back onto the bottom of the motor housing with nail varnish. One the varnish is dry a nylon bolt can be threaded into the nut and turned until the vertical slack is removed from the motor shaft; has anyone tried this?
Glad it worked, cheap fix.