Help required . Mark iii fuse blown constantly

[DavidSmith0610]

Hello , I need help to fix my mark iii amp . I have not switched on the amp for nearly 6 months and today I tried to switch it on , the 2.5a fuse constantly blown . Can any one help to identify the cause ?

I tried to remove the two power tubes and the fuse still blown after I turn the power on ( fuse is ok when it is in standby mode ) .

 

[Vinzenz]

Most likely one ore more of the hv- diodes is shorted