A classic story : playing live music next to the bar ( with the mixer right under it ). A guy did a bad move : a full glass of alcohol with orange juice fell right on the mixer. After an extremly unpleasant sound experience made of BZZZ, Biouuu Bam !
But surprisingly , the mixer handled it and we went to the end of the gig. Back home, I found out that 2 of the 10 track of my soundcraft were dead silent.
I would be very happy to have them back , so here I am asking for some help and advices. Anyone any ideas of what component would be faulty after a fresh drink ?
Both the line entry and the mic entry are not transmitting any sound to the master fader. And to me , the liquid seems tah had been spilled on the preamp part of the board ( next to the plug, upper part of the console ).
Any one ever had that kind of trouble ? Thanks in advance to any helps from you guys;
I upload the elecrtonic scheme, pictures will come soon
But surprisingly , the mixer handled it and we went to the end of the gig. Back home, I found out that 2 of the 10 track of my soundcraft were dead silent.
I would be very happy to have them back , so here I am asking for some help and advices. Anyone any ideas of what component would be faulty after a fresh drink ?
Both the line entry and the mic entry are not transmitting any sound to the master fader. And to me , the liquid seems tah had been spilled on the preamp part of the board ( next to the plug, upper part of the console ).
Any one ever had that kind of trouble ? Thanks in advance to any helps from you guys;
I upload the elecrtonic scheme, pictures will come soon
The power supply must be ok. Could have gummed up some of the pots.
Try some fader lube in the nonworking ones.
https://www.amazon.com/Hosa-F5S-H6-DeoxIT-FaderLube-Spray/dp/B00006LVF1/ref=asc_df_B00006LVF1/
Try some fader lube in the nonworking ones.
https://www.amazon.com/Hosa-F5S-H6-DeoxIT-FaderLube-Spray/dp/B00006LVF1/ref=asc_df_B00006LVF1/
Remove the parts that got hammered, and rinse them in methylated spirits (place them in a closed container filled with methylated spirits and then shake shake shake...) Then, apply the special lube for the gliders... or just get the new parts (if available). The PCB will need to be washed as well... I use a toothbrush and said methylated spirits. Good luck.
mixed drinks with pop or sugary juices are some of the absolute worst to clean especially from faders, i'd recommend steam cleaning before any electrical contact cleaner is used as that seems to in some cases to make things worse like seizing up pots.
which two channels?
which two channels?
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Use water first, after removing from board, as you have remnants of sugary stuff, which turns into carbon when subject to electric current.
Then as above.
If they are old, and you suspect wear, replace them.
I would clean the entire unit with water, hose it down, and sun dry it.
Then as above.
If they are old, and you suspect wear, replace them.
I would clean the entire unit with water, hose it down, and sun dry it.
So I opened the beast , and things were not that very messy. Actually some components were covered by some dirty dried stuff , but on tracks that are still working.
But on my two failling tracks (2 and 3 starting from left) , i immediatly spotted kind of burned and dirty stuff leaked from the pre-amp potentiometers . You can zoom on that picture to see it :
Visually , they are the only things who seems to be bad.
i already clean them , but still not working.
What do you think , should I go for it and changed them ?
But on my two failling tracks (2 and 3 starting from left) , i immediatly spotted kind of burned and dirty stuff leaked from the pre-amp potentiometers . You can zoom on that picture to see it :
Visually , they are the only things who seems to be bad.
i already clean them , but still not working.
What do you think , should I go for it and changed them ?
modestly yes , i can work on "big" component , but not all the tiny ones that this console has ( and they are awfully closed to each other)
Use extension wires before fitting, check if anything else is damaged, repair that before fitting the pots in place.
Cleaned up a friends mixer some years ago that took a lot of beer dumped into it, ran in through jacks and faders.
Told him to pick up a few gallon of distilled water and some denatured alcohol( methylated spirits) on the way over. Washed the boards in water than with a water alcohol mix with and old tooth brush, set them in the sun to dry, cleaned the jacks with deoxit and lubed the fades.
It worked fine for years until he went digital.
Told him to pick up a few gallon of distilled water and some denatured alcohol( methylated spirits) on the way over. Washed the boards in water than with a water alcohol mix with and old tooth brush, set them in the sun to dry, cleaned the jacks with deoxit and lubed the fades.
It worked fine for years until he went digital.
so all the op-amps seeing proper voltage?
the stuff at the base of the pots looks like caramelized sugar...aren't those the gain controls?
the stuff at the base of the pots looks like caramelized sugar...aren't those the gain controls?
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yes , all the op-amps are receiving proper voltage , they were even sending some interference signals on the master channel while measuring.
And yes , the dirty potentiometers on the picture are the gain control.
This is good advice.
Make sure to use DISTILLED water, as tap water is somewhat electrically conductive, and can leave trace elements behind.
I agree with the others to just replace any pots that remain wonky afterwards, but it you decide to clean them then use real pot cleaner, not a combination spray. - And not "Contact cleaner" or "switch cleaner" as they are too aggressive. - Then when dry, use a VERY small amount of pot lube. I like CAIG blue, but not sure if they still make it. I think their current "Fader Lube F" series is pretty close. It's made for plastic contacts but also works on metal ones.
I assume you know how to spot obviously blown caps, and how to test resistors, yes?
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This is a simple repair ... play a 1k test sine wave into the channel input and trace the signal down the channels that are dead till you find the problem. If you haven't got an oscilloscope then build a simple audio tracer : https://diy-fever.com/misc/audio-probe/
It'll take about 5mins to find problem ... 🙂
It'll take about 5mins to find problem ... 🙂