After a recording session the d8b started to do weird things: Faders moving slowly and all the panning leds of the desk moving on their own. I switched off and went inside the mixer. I had a similar problem in the past were the culprit was a bad fader bank. I tested the mixer by pulling out the ribbon cables of the fader bank one by one and after some diagnosis the 9fader bank seemed to be the problem. I replaced the 9 fader bank with one that i had in store and it seemed that all went back to normal...however i smelled a foul smell of burning....!!! My heart stopped
The channels 13,14 & 15 on the meter started going up and down intermittently. I popped in a headphone and heard noise coming and going. I went into the d8b after a very well search for the burnt thing inside the d8b and i saw a ceramic cap on the line control surface card burnt. This is a large card that controls the preamps from 13 to 24 channels. As mentioned a ceramic cap on channel 16 was burnt out. what was the cause? i don't know. I tried to clean the burnt area and also disabled the preamp by removing the passive components responsible for that preamp. I also bridged the connection so that preamps 13,14 &15 will still work since after the incident happened the channel before channel 16 were not working apart from that noise. It was successful. I reseated the card and after a while i saw some burning fumes getting out from the vents behind the meter bridge during that problem the mackie starting to act weired....the same problem that i had at the beginging....moving faders at a slow pace and moving pan leds. Switched off immediately and wnet into the d8b again. i disconnected the control surface card (please note that the areas that i bridged was burnt again) and started the d8b with no surface card. The d8b mannaged to boot and i connected it to the motu sound card and cubase to check that all is working apart from the surface control card which i ordered immediately from someone.
Well it wasnt nice to hear that the d8b is not producing the same sound. I plugged a clean guitar to hear if there are any changes in the sound and the problem is that you have to put the preamp nearly full to hear the sound of the guitar. The signal was weak. In some other channels is barely audible even if you crank the preamp full.
Then i removed the bridged part i soldered on channel 16 and reseated the control card back since i though that the mixer cannot work well without the control surface card installed. I did that and the mixer still had the volume problem. You have to crank the preamps full to hear something and some channels does not work when you input an instrument.
What do you think i has gone wrong apart from the line control surface card? Is it a DCA, ANALOG, DSP or CODEC fault? Shall i wait for the control surface part to arrive and then keep on diagnosing or shall i try in finding one of the cards mentioned i.e DCA, ANALOG, DSP or CODEC ?
I 'm stuck. Btw the fumes and burning problem has now went away and the d8b is stable however the problem of the low preamp volume is the problem now.
thanks
Carlo
