I recommend highly Mend It Mark ( https://www.youtube.com/MendItMark https://www.youtube.com/MendItMark ) ... his techniques are solid and over time he has fixe

I recommend highly Mend It Mark ( https://www.youtube.com/MendItMark https://www.youtube.com/MendItMark ) ... his techniques are solid and over time he has fixed one of everything. Important is the focus on standard attacks on the problem. Even his occasional mistakes and changes of tactics are well explained and make valuable lessons of their own.