Mackie DFX-6 mixer

[dmeek]

Customer just brought me this, said he just turned it on and it started smoking. After cleaning off the soot I see 4 resistors and some traces have vaporized. Also 3 smd caps are shorted C269, C264 and C250.
I'm guessing there was condensation on the board. This might be a write-off but does anyone, by chance, have one open and can take close-up photo of the traces in this area?

[Jon Snell]

I think it has gone too far to try and get a 15 year old cheap mixer on the road again, unless you can find a donor board. I wonder what they plugged into the line input socket to do all that damage.

[dmeek]

Customer is willing to trash it so that may happen. He runs a company that provides sound for outdoor fairs and the equipment is left in the truck overnight. It's been humid here lately so I suspect condensation.

[Jon Snell]

I suspect incorrect wiring. Just my experience.
Humidity will affect more than one piece of equipment and usually produces lots of noises warning the user not to let it cook.
Scenario; Plug a mixer in with a grounded mains lead, (as you should), plug in an old widow maker amplifier into the line in socket and that will be the result.