Marantz TT42 turntable help

Lee1ones

Hi, new member here. Apologies if this question has already come up already. Nothing came up in searches.

I have a marantz tt42 turntable which is playing slow. I changed the belt recently and I’m pretty confident that’s not the issue as it’s nice and tight. (Can they be too tight?)

does anyone happen to know if speed adjustments can be made, and if so how.

have downloaded the user & service manuals but nothing is mentioned.

thanks in advance.