I am not interested to amp repair in Japan to do a turntable repair or maintenance ..... by my ability I know how to do it myself.
Obviously you don't, otherwise you wouldn't spend all this time on audio forums asking the same question.
There are in fact places in Japan where you could source a manual, but your lack of understanding of Japanese language and culture will unfortunately be a barrier.
Best you bin the TT801 and then all your troubles will be over.