Re: Mackie CR4 amplifier no sound
An update regarding that R22 resistor.
On the working unit, this R22 instantly reads at a steady 10.02kOhm value no matter which way I connect the probes to its contacts, it simply remains consistent.
On the faulty unit, when I place the black probe on the contact connected to the the ground and also to the emitter of Q1, and the red probe on the other contact, I get a steday ~12kOhm reading. If I switch the probes I get around 8.4kOhm slowly increasing to around 9kOhm and then the increment becomes very slow but it's still there. All this is far different than on the working unit. And remember I desoldered and tested that R22 and it was within its specs ~10kOhm.
Does this indicate anything? Can a faulty transistor induce these results? I still haven't desoldered/replaced the transistor as I'd like to be sure I dont't have to deal with the unsoldering of that SMD unless we can conclude it is a definite cause.
I also tested Q1 and Q2 of the workng unit in the diode mode for NPN, both show equal results between themselves, and I get those same results between the Q1 and Q2 of the faulty unit, kind of makes me postpone the transistor replacement as all four of them show almost identical readings in diode test mode.
An update regarding that R22 resistor.
On the working unit, this R22 instantly reads at a steady 10.02kOhm value no matter which way I connect the probes to its contacts, it simply remains consistent.
On the faulty unit, when I place the black probe on the contact connected to the the ground and also to the emitter of Q1, and the red probe on the other contact, I get a steday ~12kOhm reading. If I switch the probes I get around 8.4kOhm slowly increasing to around 9kOhm and then the increment becomes very slow but it's still there. All this is far different than on the working unit. And remember I desoldered and tested that R22 and it was within its specs ~10kOhm.
Does this indicate anything? Can a faulty transistor induce these results? I still haven't desoldered/replaced the transistor as I'd like to be sure I dont't have to deal with the unsoldering of that SMD unless we can conclude it is a definite cause.
I also tested Q1 and Q2 of the workng unit in the diode mode for NPN, both show equal results between themselves, and I get those same results between the Q1 and Q2 of the faulty unit, kind of makes me postpone the transistor replacement as all four of them show almost identical readings in diode test mode.
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