Question: Best Practices for Mixing Desk Maintenance?

[Raveshaper]

I have a Tascam M-2516 like the one pictured above, but it is giving me a ton of crackle in the master fader and the stereo bus is giving out on one side unless I push the level above unity gain. I know I need to clean it and see if there's anything critically wrong with the master fader -- like corrosion -- but there are a ton of screws on nearly every side. The owner's manual doesn't give a rundown of how to open this thing up, so I'm hoping someone here knows the general procedure for items of this type.

My best guess would be to remove all of the knobs and arrange them by placement on some paper or in some dividing trays, leave all the faders screwed on, then remove the one(s) I need to give extra attention to and deep clean them. But I'm not sure. I would hate to disconnect more than I need to and make it harder to reassemble. Or worse yet, damage something by having it fall inside on to something sensitive.

Really hoping to go fully DIY on this. Any advice?

[bpmorton]

have you tried this link yet?

http://www.manualsdrive.com/results.php ... T7WrpMe2Me

It's getting harder and harder to fix old equipment like this. In my area the only authorized repair place (for a lot of brands) is ran by an idiot. I've had to repair some of my own equipment because of this. Just small things like changing out LCD displays and rotary encoders in synths. I myself would not want to tackle a monster mixing board like that.

Brian

[normen.]

Did you try to simply move the fader a couple of times (10s of times at least) up and down? That can sometimes alleviate such issues by simply scratching off the corrosion.

[jfrichards]

Did you try to simply move the fader a couple of times (10s of times at least) up and down? That can sometimes alleviate such issues by simply scratching off the corrosion.

This ^.  Move them quickly up and down several times, like DJ QBert (protecting the top and bottom of the throw with other fingers so you don't bang the travel ends).  There is also electrical contact cleaner available.  A millisecond squirt with the guide tube attached into the fader slot and a little QBert action can do wonders.  Same with XLR, phone, and phono jacks (but not fast in-and-out action with the plugs.  Twisting the phone and phono plugs is sometimes enough).

[normen.]

This ^.  Move them quickly up and down several times, like DJ QBert (protecting the top and bottom of the throw with other fingers so you don't bang the travel ends).  There is also electrical contact cleaner available.  A millisecond squirt with the guide tube attached into the fader slot and a little QBert action can do wonders.  Same with XLR, phone, and phono jacks (but not fast in-and-out action with the plugs.  Twisting the phone and phono plugs is sometimes enough).

You gotta be *really* careful with contact cleaner though, in the worst case it simply spreads the rust all over your gear. Apply it *very* gently if you must. Ideally you'd first solder out the fader in question and do it outside of the device.

[eusti]

People on the Analogue Heaven list seem to feel contact cleaner is not recommended in most cases for analogue synths...
No clue myself and not sure how it relates to mixer faders...

D.

[normen.]

People on the Analogue Heaven list seem to feel contact cleaner is not recommended in most cases for analogue synths...
No clue myself and not sure how it relates to mixer faders...

D.

I guess mostly because of what I said, also it can fill up caps and other parts and change their properties, which can be devastating for synths. To clean a fader or pot however it should work fine -- if its only applied to that fader or pot, which is why I mentioned taking out the part first or being VERY careful when using it.

[jfrichards]

People on the Analogue Heaven list seem to feel contact cleaner is not recommended in most cases for analogue synths...
No clue myself and not sure how it relates to mixer faders...

D.

There is a skill to using contact cleaner and it is not used for circuits and circuit boards.  It's usually used for potentiometers only (sliding or rotational) and for those pots with difficult or impossible access.  If you can access and open a pot to clean it, that's a better way to go.  Since it works by physical action, loosening up oil, dirt, and oxidation and then evaporating, it can leave the oil and particulate in a different spot if not done right.  It's certainly not a good idea to spray into a synth and then shake the whole synth.  But sometimes it's enough to spray a little in and twist/slide the pot so that a clear swipe path is created.  Before the liquid has evaporated, the oil and particulate can drip down across the swipe path.  Another method is to saturate the pot so all the oil and particulate drips away from the swipe path, but as Normen points out, that can move it to another place in the device.

FYI, it is also fairly common for crackling and bad connection to be caused by "dry" solder joints where the original soldering did not create a hot enough metal pathway and a minute crack develops.  These joints have to be re-soldered.

[eusti]

Thank you both Normen and John for explaining this more!

I appreciate it! I didn't mean to imply that you were incorrect. Sorry, if it came across like that!

D.