Naomi Universal Cabinet 29E31S & Wei-Ya C3129A issue

[Violent Ken]

Hi there!

Got a Wei-Ya C3129A chassis fully tested and functional and I plugged it on my Naomi Universal Cabinet monitor (Shanghai Novel 73SX707Y22) and when I tested it, the monitor makes a strange noise coming from the tube (I suppose?)

Tested with an other Wei-Ya C3129A chassis and the sound is the same too...

The monitor is functionnal with the old Sanwa 29E31S...

Is there any mod to do on the neck board or the chassis?

Thanks for your answers!