Mixing Board troubleshooting

[dwunder111]

I have a Mackie CFX16mkll mixing board that is about 12 years old. Most of that time it has been stored in a climate controlled environment. It has been working fine everytime I use it but tonite I powered it up and a tremendous continuous popping sound was emitted. The volume faders wouldn't lessen it nor would disconnecting all the cords. I checked all other devices and even ran my computer thru the PA without the board to make sure the power amp etc were not the problem. I reconnected the board (using different cords) and it worked for about 30 seconds, then the continuous popping ensued. I can turn it off and back on and this same process occurs. Obviously something is screwed up in the mixer, the popping starts out at about 3 per second and gradually increases in frequency until its at 10-15 per second. Why does it work for a few seconds is what I'm wondering, if its blown it should be blown. Any ideas? Thanks

Doug

 

[Massive Master]

Is there any possibility that there is phantom power hitting somewhere it shouldn't be? Are the outputs of the mixer connected directly to the PA or is there something before it? A crossover network, another mixer, etc. -- I know it's a longshot, but this early, it's the only thing I can come up with.

 

[Chili]

Why does it work for a few seconds is what I'm wondering, if its blown it should be blown.

Heat. As it warms up, whatever is the cause gets worse. Or a bad capacitor. Or both.

Sounds like a bad power supply to the final stage amps. Yes, the board has amps, just not power amps like in a PA. If you are hesitant to open it yourself, you should find a technician who can repair it. I bet it is not an expensive repair if the guy has the right schematics and resources.

 

[bouldersoundguy]

Honestly, a CFX is not a mixer I'd spend and time, money or effort fixing. By the time you get it working you might have spent half the resources needed to get a better mixer.

Yeah, it's probably a cracked solder joint somewhere that is intermittently resistive depending on temperature. That's not really a complicated thing to fix, but the time spent opening up the unit and either finding the bad solder joint or just resoldering everything is what will cost you.