Kurzweil 1000 series expander

Hello everybody! Hope you’re all safe! I own a 1000PX and and since I bought it a year ago it produces a quite loud humming sound and it also overheats a lot. Is it normal or should I recap the whole power supply or change the transformer? Also I’d like to expand it to a 1200 Pro 1, has someone done it with the info provided in k1000.net? Thanks!