After i replaced the transistors (all of them) from one channel, i checked for any shorcuts, open resistors, diodes... everything ok, i install only 2 transistors 2SA1943 and 2SC5200. Output: 2,15v and dropping. Theres no voltage drop across, R18 (0v), in Z4 its only 0,9v. I perform the same repair procedure in the other channel and its work great.

 

Solved, C16 (4.7uf/160v) was open.