DIY-990 burning R36 Lola Mic Pre

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imanerd808

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Joined
Apr 1, 2019
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5
I soldered R14 wrong on one of my DIY-990 op amps and when powering up it started to smoke. After looking at the board I see that R36 is burnt. looking at the DIY-990 I found R14 backwards and the resistor pushed up against the MJE171G transistor. If I swap the orientation of the resistor and replace R36 should this fix the problem? is there a chance I screwed up the Transistor? or both transistors? any help would be appreciated.
 

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Maybe I'm too late, but anyway. Most probably output transistors survived (a short between output of DOA and +Vcc or -Vee) because of protection resistors.  You should change the burned resistor and try it again. You can first check the transistors using diode position on your DMM. It's important that the resistance between  collector and emitter is high in both direction.

 

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