Combo compatibility

my combo (qsi sbw 241) is out of repair now. i can not find a new one. So, i am looking for a combo; any brand, any model which is identical and 100% compatible to qsi sbw 241, so that, i can replace my damaged combo.

i write to this forum, because i was told that this issue required a detailed tecnical knowledge and buying a wrong replacement was a high possibility.

thank you for you time.

regards

hasim