Luxkit A503/Z503 curcuit schematic/build instuction wanted

[Frank J.Y. Lin]

Dear all,

I have a luxkit old tuner A503/Z503 and enjoy it very much.
Unfortunately, it was out of work recently.
I am looking for it's curcuit diagram / build instuction to fix it.
I am woundering if somebody can help me.
Thanks for your kind assistance in advance.

best regards,
Frank