Hi, I solved the problem. I used two small 2VA AC transformers that I soldered onto a small breadboard with 2.54mm pin headers at the location of the broken transformer. 230V/2x18V 2VA, 230V /2x6V 2VA. The 230V: 2x18V only were soldered directly behind the mains fuse on the primary side, because there´s only 120V on the PSU board, which was just right for the 2x6V transformer to generate the 2x 2.5V filament voltage. Please pay attention to your country-specific mains voltage in order to select the correct transformers.