In the diagram, what corresponds to the output stage will leave some resistance highlighted, check that R913 = 100 Ω 1/4 W is not open or altered, check that in R925 = 0.1 Ω 1W and R926 = 0.1 Ω 1W there is no voltage .
If there is a problem at any of the points indicated, it is a reason for the equipment to protect itself.
It is always a pleasure to help those who have problems, in the same way I tell you that in me you have a friend here in Valledupar Colombia.
blessings friend.