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Old 10-06-2020, 07:50 PM   #26
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Default Re: troubleshooting definitive technology prosub 60

Originally Posted by khajr View Post
Hey momaka...Sorry I was referring to the pins for that mosfet. 1 is gate, 2 is drain, and 3 is source.
Ah OK.

In that case, Q4 and/or the sub-circuit around Q4 are definitely suspect, because you have 6V on the Gate of Q7, which means it's going to conduct as soon as a MOSFET is installed.

Originally Posted by khajr View Post
I will also check C21 and C27 and C5 and C6. Thanks so much for your help.
No problems.

Just to be clear, we are looking for the voltages across these caps (but if you want to take out and check the caps with a cap meter in addition to measuring the voltages, that would be fine too.) An unbalance in the P15V and N15V voltage rails could also be the reason why there is a voltage on the Gate of Q7.
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