problem with z axis on tronxy x5sa pro

[shakle]

fixed the problem! a few screws had entered the pulley... at the first calibration there were some clicks on the axes but now the plate has arrived on top .. what should I do? it's my first printer...edit: i went to z offset. the head has scratched the bed....calibration it's ok.Now the problem is when i try to print file on microsd.The first layer doesnt stick on the bed. How can i fix ???