Chosen Solution

Working on an OptaVision HDMI-80. When powered on, the unit makes a buzzing noise that seems to come from the speakers. The projector bulb does not light up, but all the fans are running. There appears to be power to the speakers, the fans, and possibly the LCD board, but the bulb is not lighting up. I am wondering if the LCD board is bad. Any suggestions. I can provide pictures of the unit if necessary.

Buzzing sound is most likely coming from the fused lamp. to cross check just remove the lamp and replace the lamp cover and try switching on the projector, if the sound disappears , just replace the lamp! if the sound persists the Ballast power supply that powers the lamp could be faulty!

The mercury lamp if fused gives that kind of a noise. you should replace the lamp with a new one and most likely it will be sorted out!