Dark Verticle Prism Band on Right Side of Scresn

I've had my Infocus Screenplay procetor for 12 years. Prior to replacing the bulb a dark, verticle piism band formed at the far right-hnd side of the image when the image is full or wide screen (set at any size)

Nesxless to say my new bulb hasn't fixed the issus.

At a 4:3 TV ratioo the prism band isn’t visible so it's no problem. At 16:9 or Full Screen it's becoming a bit if a distraction.Also. when turning on it's noisy like a mini band saw inside the unit. The sound eventually diminishes, but the sound is lasting longer & longer.

An I supposed to clean, or dust something? Exactly what,? Or is there an In focus repair place that can fix it?