Signature 22MTK Bad Channel
fbarrosp
Posts: 1
Hello, I recently detected one of the channels of my 5 year old mixer has gone bad. It is the channel 8 that has the limiter and HI-Z modules. When I put an input signal the it has a very low level and the gain knob does a noise sound when turned either way. I opened it and measured with a voltimeter and an osciloscope and detected that the signal gets lost in the IC1 at the V- input. Since the signal is balanced, I measured both signal lines and the same occurred in both of them: DC voltage around 7.4v, but no AC signal in neither pins 2 nor 6. I compared it to the channel 7, which has the same modules and share some of the IC's with channel 8. I have inspected the circuit for blown up components and everything looks good. The supply voltages are ok and capacitors seem ok. I measured all components and they seem to be ok. I can give the measured data but first I want to ask you if you have the schematic for the 22 MTK version, the most similar I could get my hands on was the 12MT. In general all camponents labels and values match but it would be better to have the corresponding schematic.
I have search if anyone has this issue but haven't found anything but USB or power supply problems.