Gildermeister CTX 400 retrofit

Hi folks , I have a Gildermeister CTX 400 in need of new electronics , ie , main boards etc .As the Heidenhain platine / boards ,on mine are defect and new parts are not avaliable .Ansd not repairable Ive been told  Could someone suggest where what I will need and where to get it all and maybe some tips would be great .        Im in Germany .Hope to hear soon   Harry