Got a 36" vacuum tube CRT Thomson Proscan from a friend, model PS36600. Picture quality is cherry, but the aspect is pinched or squeezed towards the center, giving it a hyperbolic shape, and the far left and right edges are offscreen. Looking for a way to adjust this setting on the board itself, since one does not appear to exist on the back of the unit. Also having a real bastard of a time finding a service manual for it.