What the heck did I do


So I pulled my platter to look at the bearing on my VPI prime. I have the eagle PSU, and the road runner tachometer that control my speed. After I re-greased the bearing I dusted the platter with one of those swiffer duster‘s and the duster went near the little PCB board that the Road Runner tach picks up at signal with. 
I put everything back together and switched on the turntable, it spins at 33.3 RPM but now the tachometer isn’t picking up any signal to control that speed. Did I statically electrically charged the PCB board and damage it?  If so what do I do now?
last_lemming
Sometimes a little dirt or dust on the Hall sensor can screw up the operation of the feedback network.  Been there.  Done that. Fixed that by just a careful cleaning.  Of course, if you did anything to alter the spatial relation between the sensor and the magnet, that too would or could cause the problem you describe.  It's rather critical that the two pass within less than a very tiny distance of each other (max distance between the two is mentioned in the instructions but I forget exactly).
every vpi is shipped with a ghost in the bearing well... don't you know that???!!
All is good. It just started working again. I have no idea why. 
To answer some quesrions i’ve been trying to figure out why I’ve been having woofer pumping (Subsonic stuff) with cartridges that should work with the arm. I’ve checked the platter, it checks out, I checked to make sure the TT was level and check that it’s secure, I’ve checked everything I can check and all was good, so figured I check the bearing and at the same time lube it,  and that’s why I took it off. 
I sure do love digital. Perfect sound forever? No...but easier sound forever, yes.
1. Check to see if the little magnet is still there. If it is, make sure it is properly aligned with the sensor.
2. You might have bumped or otherwise slightly moved the sensor when you removed your platter. It needs to be very close to the platter. 
Why did you feel a need to just look at the bearing?
Do a once a year lube/cleaning.
Last_lemming you sure you did not knock the target off the platter?
If you did not and everything is hooked up correctly then the sensor on the PC board is bad. You can try shocking it with some freon to see if you can free it up otherwise it will have to be replaced. Maybe it is still under warranty? 
Could be. Could also be you got something on whatever sensor that thing uses to read speed. Probably just needs a reboot. Unplug it, look everything over real good, plug back in. Sorry. Make that plug back in, power on, cross fingers...