On page 97 of Silicon Chip July 2014 issue, Rodney Champness mentions and shows the jig he uses to observe the operation of turntables during maintenance.

It's a simple arrangement of a board containing a matrix of holes with the turntable suspended above it via 300mm dowel rods.

I don't deal with turntables but I thought it might be of interest to those who do.

I see that. There is a thread on here about the same device for holding chassis'.

Yes, I recall that thread, but thought I'd put a reference here for those brave souls who dare to take on turntable repairs.

Now having just said that I don't do such repairs, I note that my AKAI AP-007 needs some attention. In the late 1970s this was a top of the line turntable with its direct drive platter and separate motor for the tone arm. I suspect its time to re-cap.

I wasn't too impressed with the dowel-farm idea for radio chassis work because changing angle would be troublesome. However I can see that it might be a good solution for turntables that need to be kept at a stable horizontal plane while being got at from below.

I'm sure that Akai turntable is worth preserving. My Luxman PD272 direct drive of the same vintage is still in regular use, though has conventional counter-balanced tone-arm. Only limitation is only 45 and 33.3rpm so won't play 78s or oddball discs.