30 year old SME 30/2

FWIW, SME revised (lowered) the viscosity of the damping fluid used in their suspended turntables at least 20 years ago resulting in a more natural, less-dark presentation.

The suspension bands are unfortunately a proprietary moulded affair which are not inexpensive and there are 60 used in the 30/2 + another used between the lower base plinth & subchassis to offset drive-belt tension. In normal low ozone environments they seem to last 10~15 years and may be swapped around if needed. A feeler gauge is part of the supplied tool kit for optimizing suspension height and establishing suspension band wear (stretch). Thoughtful design allows variable damping through suspension gap.

Owner’s manuals are available on their website which show users more detail than is typically provided:

https://sme.co.uk/service/manuals/

SME are virtually bomb proof and stand the test of time IMO.

I bought a second-hand limited version of the SME30 / 12A with SME V-12. Some questions have occurred when I debug this player. When I adjust the column gap to meet the gauge A terminal, press the 33 button, the speed is accurate and stable, but the light continues to flash and cannot be locked, and the upper board has obvious swing. But when I lowered about 1mm, this phenomenon disappeared and everything was normal . This phenomenon has not appeared in two states in 45 and 78, they can be locked quickly.

What could be the reason for this?

Thanks