Numark CM100 mixer buzz

Good day all.

Firstly, happy belated 2025 to you all.

Need soem advice pls. My Numark mixer, after many years of faithfull service has developed a buzz. Literally just happend a few days ago. Even with nothign connected, no input signal, no speakers, nothing. Only plugged into the mains, and with switch on, I hear a kinda high pitched buzz right by the transformer.

I suspect a transformer issue, but not able to say exactly.

Any help would be appreciated. Thanx