Spin the platter by hand before you push the power button. Both of my VPI TT's do the exact same thing.
Classic 3 VPI
My Classic 3"s belt squeals upon turn on. After a couple of seconds, the squealing stops. I've tightened the pulley, installed a new belt and did what VPI recommended, I powdered the belt. After applying powder, the squeal quietened but squealed again on the very next try. I reapplied powder and the same thing happened. Any advice is welcomed.