500W PA amplifier with Limiter

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pls help.

here is my b500.
first powering up with fuses 53vdc,0,53vdc amp works fine.
i used 2sd669a instead mje340. it works fine .
after one hour i change mje350 to b649a. in near d669a 100ohm resistor burned and fuses blown.
after i remove d669 and 649 with mje340,350 but same problem fuses blown.
can any body help to solve this problem.
 

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