Cleaning/Servicing a PA Mixer

[thebrig]

I've just acquired a Behringer XENYX X2222USB, it's a bit grubby, and some of the pots and sliders are a bit crackly.

 

I'm quite practically minded and would like to take it apart, taking photos along the way to ensure I put everything back properly, and give everything a good clean with compressed air cans etc.

 

I was told by the previous owner that the mixer works as it should, but is just a bit crackly on some channels.

 

So my question is: After doing all this, will all the crackles disappear, or am I wasting my time trying to restore it to working order?

[Happy Jack]

If I were you, I'd abandon any notions of dismantling it until you've hit it with a decent application of switch cleaner. You may find that's enough on its own to sort out the crackles.

 

[SamIAm]

9 minutes ago, Happy Jack said:

If I were you, I'd abandon any notions of dismantling it until you've hit it with a decent application of switch cleaner. You may find that's enough on its own to sort out the crackles.

 

+1

[Chienmortbb]

Having worked on Behringer mixers, I would not try to do too much inside. Yes shoot some cleaner, Preferably DeOxit as it is designed for pots. The other thing to try is literally rotating the knobs back and forth 20-30 times, sweeping the full rotation of the pot. it helps temporarily to clear some of the clag.

[police squad]

yep, deoxit is the stuff

[Phil Starr]

23 hours ago, thebrig said:

I've just acquired a Behringer XENYX X2222USB, it's a bit grubby, and some of the pots and sliders are a bit crackly.

 

I'm quite practically minded and would like to take it apart, taking photos along the way to ensure I put everything back properly, and give everything a good clean with compressed air cans etc.

 

I was told by the previous owner that the mixer works as it should, but is just a bit crackly on some channels.

 

So my question is: After doing all this, will all the crackles disappear, or am I wasting my time trying to restore it to working order?

 

Wasting your time? Not really but don't expect a miracle and don't create any further damage which means working minimally rather than doing work which is unnecessary. I see you can still buy these for £259 and by and large the Xenyx mixers are pretty reliable but time will take a toll. At that point it won't be worth paying a tech to try a fix which might only last a short while.

 

Obviously the sliders are the most vulnerable bits, they are probably the most often used parts and the tracks are poorly sealed against dust, The first thing I would do would be to clean the outside of the mixer as thouroughly as possible avoiding driving anything into the sliders in particular but the innrds generally. Anything left on the outside you will displace with handling and it could end up inside. Don't use liquid cleaners including water. instead use moistened cloths or cotton buds and you are trying to lift dirt not wash it off. If your cotton bud releases a drop of water when you use it you are far too wet. I'd risk using a little washing up liquid in my water, nothing stronger. Personally I remove all the knobs before starting all this, they can be washed separately and dried thoroughly before reinstalling.

 

My next step would be to investigate what is working and what not, I'd be very reluctant to clean a slider that was working ok 'just in case'. The Deoxit or Servisol don't really clean dirt, they soften it and then whan you wriggle the controls they move it around, nothing actually washes out of the pots. On a working/non crackling pot it could end up creating a fault that wasn't there before, on a really crackly pot it often works a treat and you hve little to lose. Make sure it's a good quality switch cleaner and never use anything like WD40 which leaves a film of lubricant. Even a switch cleaner will leave some residue so don't soak everything and watch out for over spray.

 

So test every control and wiggling ten times before testing is a great start in cleaning the dust of ages. Note what crackles and what doesn't. If it crackles is that across the travel of the control or just at the extremes. I've got one that just crackles at the bottom end which I don't use anyway so I leave that alone. Obviously if it crackles when you adjust the control but only when you move it that is less serious than something which crackles when it is static. Hopefully you can leave more than half your controls alone.

 

I've had great results on sliders You can get the cleaner onto the tracks inside through the dust seals easily enough and the dirt if it is in there will generally get moved to the ends of the sliders. Go for the worst one first as you'll have little to lose. The rotary pots are more problemmatic. They will probably be more or less sealed so getting switch cleaner in can be really difficult. often impossible without opening the whole mixer up and getting inside which makes the circuit board vulnerable. I'd give it a look but I learned by breaking more things than I fixed at first.

 

I'm agnostic about compressed air, I've a compressor at home so I've never used a can and I can set the pressure. I'd certainly not use it like I do on car parts but I have cleared a lot of dust and spider webs off circuit boards in the past just be aware that several psi on a delicate component isn't a great idea. I guess the question is "do you feel lucky"

 

Don't forget all the sockets, try them all and try plugging and unplugging repeatedly. Switch cleaner can help here but i'd spray the plug I was using and not the sockets as you don't know what is on the inside of your mixer, replacing the plug is going to be a lot simpler than repacing a pcb mounted socket specially made for Behringer 20 years ago.

 

Will all the crackles miraculously disappear, probably not. Will you end up with a bargain price usable mixer? With a little luck you should be OK, what have you got to lose?

[Chienmortbb]

All good advice @Phil Starrbut one thing to say about dust. Mos of the dust/debris inside pots is caused by bits of carbon that flake off the track in use. It’s one of the reasons I chose conductive plastic pots on my builds.  They last more than twice as long as carbon pots but of course also last twice as long at least. 
 

From a manufacturer’s point of view, especially a “value” brand such as Behringer, the extra cost of pots with a conductive plastic track could make a mixer uncompetitive. 

[thebrig]

Thanks for all the advice guys.👍