Fixing dj mixer left output

Hi I have Ecler nuo 2.0 dj mixer. It has this faulty left master output. Everything else works perfectly. The left output gives mostly noise. When cranking volume very high a little bit of music goes thru the left output.

Any ideas how should I approach this. I was thinking to open it up and clean with proper electrical cleaning spray. But if that's not enough to fix the problem what should I try next.

I hope this is the right forum to ask. I appreciate all the answers, thanks guys and gals 👍!
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My mixer had 1 a worn out master volume pot.
2. a cracked through board via from top to bottom.
New pot, patch wire between part leads, good as new.
found it by tracing music through the circuit. Use a sound probe, a scope, an analog VOM on 2.5 vac scale with a .47 uf cap between negative lead & analog ground. I used the last. Didn't even have a schematic diagram. Just a datasheet on the op amps to show the ins and the outs. Pots I figured out pinout by turning power off, measuring various pins to other pins with the 20kohm scale of a DVM.
there was a bus between the input channels on the pots, figured that out by looking for 0 ohms on adjacent pots.
Powered mixers sometimes blow the IC due to a shorted speaker wire. For that you'll need a 25 or 50 vac scale.
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If you're worried only test with the lid on. Unplug before taking the lid off so no mains voltages inside.

Those leaking caps (if that's what the dicoloration is) need replacing, which requires desoldering (something you will need to practice on a scrap board if you've not done it before).

However there could easily be other faults present.

Check carefully the output socket solder joints, its common to get cracks forming due to mechanical abuse of connectors.
Safety rules. Touch metal with the power on only with one hand. Electricity over 24 v from hand to hand can stop your heart. Keep other hand in your pocket if you are impulsive. Take measurements with a clip lead from meter negative to ground, which you can install with one hand. Then measure with the other probe.
Wear no metal on hands neck fingers. 1 v can burn your finger to charcoal through a ring.
Don't touch metal in the product until you have determined with meter that it is < 1 v to case ground and analog ground. Capacitors can store electricity for days. If found charged up, discharge with a resistor with insulated wiring to ground. Don't touch the resistor metal either, just the wire insulation or a probe.
Wear safety glasses soldering, especially desoldering. Solder splashes and can burn your eye.
Don't work alone. Don't work distracted by people or media.
Mixers without an amp section are one of the safer devices to learn to work on. A soldering tutorial is run by
MOS devices can be damaged by static charge. Not usual in mixers, but wear safety strap to ground installing or removing MOS type parts. Part datasheets on Search engines can often find device schematic diagrams.
This device if you paid < $30 for it may be quite suitable to butcher as your first project. If not there are other mixers for parts or repair on e-bay/craigslist/gumtree/facebook . I started on car radios, which unfortunately had 400 v in them in 1956. The book I had was for 1959, when tube plates were 12v. SURPRISE! Safety warnings weren't in the service manuals then. I shorted thumb to finger, which did not stop my heart.
Tip when measuring with probe - don't touch two pins at a time. It blows things up that you have to later replace. IC's particularly. A lead of a resistor is usually better to touch than a multipin IC.
Great devices to learn on are heathkit, dynaco, peavey. Well documented, lots of threads about them.
Have fun learning & maybe repairing.
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”Mixers without an amp section are one of the safer devices to learn to work on”
Do you know if this Ecler Nuo 2.0 has one? I’m not sure. It’s a dj mixer so it has two phono channels...

I’ve done some soldering and I think I could pretty easily change the damaged caps. I’m slowly gathering some information to decide how should I proceed. I’m gonna go with the safety first tactics.

Thanks for all the comments so far!
The component that stores charge is the capacitor. Electrolytic capacitors store the most charge. Those are the ones that need changing. Rubber seals deteriorate due to time, heat, oxygen from the air, the water leaks out, ZOT!
Turntables can build up static on the platter in dry environments, which can be very annoying but usually not lethal.
Mains electricity like the fuse, the lightning and surge protection disks, the transformer input, can be lethal. Work this area only unplugged. 120 vac minimum at current high enough to create liquid metal spatter around a short. Modern switcher supplies have a Mains voltage rectifier & capacitor (200-400v rating); these MUST be discharged with resistor before touching metal or changing.
If you follow the rules in post 11 in the mixer area, the most that would happen would be a shock from finger to thumb at <90 v. Annoying but not likely to cause permanent damage. Vacuum tube amps, TV's and CRT monitors are much more dangerous. Don't repair the switcher supply area. They blow up too many parts to be economic to repair, and are not for newbies in any case. I've done 2 but I've been at this since 1958.
When changing electrolytic capacitors, make sure to the + is marked on the board before removing the old one. If you put one in backwards it explodes when powering up. Mark board with sharpie if neceesary. Wear safety glasses when powering up.
I buy electrolytic capacitors with service life ratings not <3000 hours, and 10000 hours when I can get them. No sense doing the job again when we can get long life parts on the internet from authorized distributors. I'd mention companies but you have no hemisphere listed, much less country. I've had to change e-caps 4 times in one hifi amp. Life is too short to install the trash from the local TV parts store anymore.
Warning-larger electrolytic capacitors that short often take out the device feeding them. A fuse you hope, or a cheap resistor. More likely the $10 power amp IC or cheaper a $5 transistor or $1 diode or rectifier bridge.
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