# Cleaning/Repairing console faders



## Radiant (Apr 7, 2008)

We use a Leprecon LPX-24 console at church. Four or five of the faders, when brought down to 0%, "creep" back up to 5% or 10%. Sometimes they stay up, sometimes they flicker between 0% and 5%. This even though the fader is physically at the bottom of it's travel. The really irksome thing is that two of these are "Playback" faders (other consoles would probably call them submasters, but Leprecon is, umm, _different_.) The moving light protocol is LTP only, so if I'm using Playback 4 at full intensity, but Playback 3 creeps up to 5%, suddenly my lights jump to a different scene! Maybe they'll even do a nifty dance between Playbacks 3 and 4! And hopefully it'll be during a very somber, introspective time!!! 
The workaround we've discovered is to very gingerly fade out the offending faders until they deactivate, but they're still a smidgen above the physical bottom. Is there a real solution for this, besides replacing parts? Can I clean them? Maybe they're corroded? 
I've never opened up a console before. I also need to replace the 3.5" floppy drive (really!!) so that I can do a show backup and hopefully install LED fixture profiles. 
Any help is appreciated! Thanks!


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## Grog12 (Apr 7, 2008)

The first thing you do too clean out an LPX-24 is throw it in the trash as it is a poor excuse for a light board much less a moving lightboard.

That being said I'd advise against you personally opening and or cleaning the board and instead contact your authroized rep/dealer down there in OK

Cowser Lee Marketing
Jim Cowser
http://www.cowserleemarketing.com
[email protected]m
800-572-6433
817-478-5262 (fax)
AR, LA, OK, TX


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## ScaredOfHeightsLD (Apr 7, 2008)

While the cleaning aspect seems like something you could do yourself with the proper cleaning product, i wouldn't recommend cracking open the console and trying to replace the disk drive yourself. It sounds like this board is in need of a serious tune up. I would recommend getting in touch with the dealer who sold you the board, see if they do factory authorized repairs/cleaning and if not, perhaps they could point you in the right direction of someone who can. As another option, give leprecon a call and see what they recommend.


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## JD (Apr 7, 2008)

Generally, non-oil based contact cleaner spray will work without opening up the board. ( like http://www.polywater.com/typefd.html ) Make sure it does not say "clean and lube" as these contain an oil which may drip all over the place. Unfortunately, most newer sliders have so much lube shoved in them that cleaning will not help, but you may end up with the lube all over the place inside the board! 

Now, the real question is "do you have dirty sliders in the first place?" Often, high use controls will actually wear out the carbon trace that is used as the resistive contact in the slider. Quite literally, when I've taken apart old ones, you can see the backing material right through where the carbon was where the metal fingers slide! If this is the case, no amount of cleaning will help! Both produce the "flicker area" effect when the slider is in that position. Although it is a simple inexpensive part, the job is usually VERY labor intensive as the backs of the sliders are almost always soldered in to a circuit board and everything has to be removed to get the fronts free prior to replacement. I would not recommend this to anyone. If some of the sliders are that worn, then it's time for a new board as the repair labor cost will be very high!


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## Van (Apr 7, 2008)

Gotta go with JD on this one. Many sliders are "self Cleaning" and while a lot of people might frown upon it, one of the first things you can do to clean out a slider < audio, video, lighting board> it to slide it up and down rather quickly, don't press down on it too hard, just slide up and down its normal travel several times really quickly. No this won't hurt it at all. Occasionally dust / dirt / cheetos get stuck between the contact and the carbon trace which is what causes the jumping. 
DO NOT USE a solvent / Cleaner , this is where I will differ with JD, using a Clean and Lube elcetronics cleaner will be your best bet to extend the life of a dirty slider. A solvent only cleaner will remove the lubricant used in the slider and cause premature wearing away of the carbon trace rendereing the slider useless, and nescessitating the replacement of the slider. I have seen boards where someone thought they were doing a good thing by, "blowing out all that gunk in there" with canned / compressed air, that clear, Vaseline like lubricant is supposed to be in there, it helps catch dust and debris, sortta like earwax and snot. 
If none of these solutions help than I wouild consider either sending it in for repair <if under warranty>, or replacing the slider yourself. It really is an extremely simply task for anyone with even a little skill in electronics.

Oh and for general knowledge;
another main cause of failure of slider is people placing excessive downpressure on the slider button itself. I have opened up boards to replace sliders and found the reataining tabs, that hold the slider itself together, bent down < away from the surface of the board> this is quickly remidied by squeezing the tabs back closed and checking the slider for travel , drag, and or rough spots.


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## TimMiller (Apr 8, 2008)

try to get through to leprecan. Your board is probably still under warranty, even if you dont even know it. I know of several churches who have gotten warranty parts and service and they didnt even know it was still under warranty. Call leprecan, and keep calling if no one returns your call.


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## Radiant (Apr 8, 2008)

The board is not covered by a warranty, as we purchased it used about 4 years ago. I sent an email to the company that did our install, perhaps they can service it as well. I wish I could tell whether the sliders are dirty, or if they're coming apart. 

Believe me, I'd love to hand-me-down this board to our college or high school group and get a Hog 3PC. But I think the accountants are a bit tired of me right now, as 1) I talked them into an extra pair of Mac 600s, 2) which necessitated a new breaker panel being installed, 3) I hit them up for a minimum number of spare lamps to keep on hand, 4) we bought new sockets and lamps for our Lekos, 5) I conferred with our kid's director for some kinda DJ flashy-spinny thing. Bottom line, I'm leery of asking for any expenditures right now, and hope I can do this myself.


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## TimMiller (Apr 8, 2008)

I'd try the self cleaning slider method described. It does work sometimes. Some cheap faders are not self cleaning. I think the lep faders are though. I havent serviced one of those consoles in a while.


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## Grog12 (Apr 8, 2008)

http://www.leprecon.com/productfiles/212085V3.2Manual.pdf

pg 213 in Adobe 209 for actual page number...worst Maitenance and Repair section.....Ever.


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## TimMiller (Apr 8, 2008)

AGREED. What a load of crap, that is just normal before you begin info. No where that i have seen does it say that you cannot wash out your entire console by pouring a bucket of water into it.


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## Grog12 (Apr 8, 2008)

TimMiller said:


> AGREED. What a load of crap, that is just normal before you begin info. No where that i have seen does it say that you cannot wash out your entire console by pouring a bucket of water into it.


Which as I've state previously is probably one of the best bets with that board!


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## David Ashton (Apr 9, 2008)

A problem no-one has mentioned is fluff build up, often fluff will fall into the sliders and get compressed at the top and bottom, stopping the fader travelling all the way or bouncing back, I use a dental probe to remove fluff and then clean with contact cleaner, never, ever wd 40 or suchlike which ruins desks, it is insulative and if it can remove gaffer goo imagine what it does to the boards.


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## JD (Apr 9, 2008)

There is one other option (but you might wreck your board!) Back in the 80's boards tended to be a sea of sliders, and needless to say, the problem was that much worse. Being stuck on the road, often for 3 weeks at one venue, you end up with a lot of time on your hands so I got quite good at this: Each week I would focus on one area of the board. I would remove the faders and pop them open. Wash them down with Freon TF, then put a thin coating of silicon lube on the inside and the resistance strip. I would then inspect and adjust the fingers, re-assemble them and put them back in the board. Over the years I found out you could do this about 4 times before the little metal prongs started to break off, or the carbon and/or fingers were worn out. Most sliders are available OEM or from a parts vendor like mouser.com. If you get into the world of parts matching, be careful! In addition to the physical match, you need to match the resistance (in ohms) and the taper type. (Liner or Logarithmic. Light boards generally use liner, logs are often found in analog sound boards.) 

Remember, the board should be unplugged (the usual disclaimer) and, if you wreck your board, it's on you


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## Radiant (Apr 9, 2008)

> There is one other option (but you might wreck your board!)




> if you wreck your board, it's on you


JD, please re-read the original post. It's a Leprecon LPX-24. It's already a wreck.


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## Grog12 (Apr 9, 2008)

Radiant said:


> JD, please re-read the original post. It's a Leprecon LPX-24. It's already a wreck.


Radiant stop insulting wrecks like that. They would be offended.


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## Radiant (Apr 9, 2008)




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## Van (Apr 9, 2008)

JD, I'm glad you posted that last post. It's something I thought about but completely forgot to include when saying," It's easy to do..." I learned the difference between linear and logrithmic tapers and Potentiometers whe I went to replace the pots in an electric guitar. Never did sound right after that.


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## kiilljoy (Apr 10, 2008)

On something of a side note, anyone know where one might find a selection of sliders? I've been looking for one of 50 ohm or 100 ohm capacity. All I have been able to find are the rotary knob type.


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## avkid (Apr 10, 2008)

You might want to try Potentiometer instead of slider.


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## Van (Apr 10, 2008)

Google "slide pot" I got hits at several surplus places, but a quick look did seem to provide mostly high values, 1k< . One place I looked had lots of "slide pot" knobs but next to no slide pots..... go figure.


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## TimMiller (Apr 11, 2008)

check out digikey and mouser they have lots of faders.


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## JD (Apr 11, 2008)

kiilljoy said:


> On something of a side note, anyone know where one might find a selection of sliders? I've been looking for one of 50 ohm or 100 ohm capacity. All I have been able to find are the rotary knob type.



Are you sure that's not 50k or 100k? I don't think I've ever ran into a slider that was 50 ohms. What board is that out of?


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## TimMiller (Apr 12, 2008)

a lot of sliders are 10k


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## JD (Apr 12, 2008)

TimMiller said:


> a lot of sliders are 10k



Yea, I would have to say 10k is probablly the norm in most boards. 50 or 100 ohms is not something I have seen, thus the thought that maybe there is a "k" after that number. 

Even at 5 volts, the drop across ten 50 ohm sliders would be one amp! Just wouldn't make sense in a light board.


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## kiilljoy (Apr 12, 2008)

sorry, I did mean 50K or 100K.

edit: The pot is controlling an architectural dimmer over a low voltage line to dim our house lights. The one that we have is really sensitive over about a half an inch space (couple of cm) and not at all over the rest of the length. Makes it hard to dim the house lights with any "theatrical effectiveness".


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## JD (Apr 12, 2008)

kiilljoy said:


> sorry, I did mean 50K or 100K.
> edit: The pot is controlling an architectural dimmer over a low voltage line to dim our house lights. The one that we have is really sensitive over about a half an inch space (couple of cm) and not at all over the rest of the length. Makes it hard to dim the house lights with any "theatrical effectiveness".



That could be caused by a couple of things. Check back through the thread for the stuff about Log vs Liner taper. Using the wrong one would cause that effect. Also, they may have wired the wrong DC buss to the control. (Most analog systems like to see 0 to 10 vdc) One other thing would be the high limit and idle adjustments. Just some thoughts. Remember, even though it is low voltage, only qualified personnel should be dealing with the problem. (Usual disclaimer) 
Mosuer.com would be a good place to start the hunt if you need a new pot, and the OEM can not be had.


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## kiilljoy (Apr 12, 2008)

The pot has a label on it IDing it as linear with a custom curve in the 10% to 0% range. I don't remember how the custom curve works out (if it's a sharper or slower curve). Looks like mouser would indeed have the pot I need, and they're practically around the corner from me.

My understanding of the history is that the pot was replaced with a bit of frankensteining because the last one was even more sensitive/ineffective. The current one was hard to find when it was replaced. I assume (ASS of U and ME) that the dimmer/pot combination worked at one time quite well, and this problem is somewhat new. 

We're looking at developing some grants to improve the lighting equipment, and we had talked briefly about replacing the house lights with LED PARS and changing the wiring, and running them on a 600W lutron dimmer, but at $200 a lamp, it wouldn't come cheap. (we actually ordered one lamp to try, except that the one we ordered turned out it didn't dim like we thought it would) In doing a bit more talking with other staff members, we thought we'd look into changing out the pot to see if that fixes the problem. After all, $3 is better than say, $2000.

Sorry for jacking the thread.


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## JD (Apr 12, 2008)

Could it be in backwards? Just a thought. You might want to also order the Liner version. There are several different curves used in lighting because filament brightness itself is not liner. Most are determined by the dimmer design, or in modern dimmers, selectable . Still, if it had a compensation curve, and was flipped around, instead of correcting the curve it would have made it twice as bad.


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## kiilljoy (Apr 12, 2008)

I had been planning on getting a linear pot actually, and trying the 50K and 100K out to see which one works better. After the past couple comments, though I was thinking of getting a log pot and trying that out too. I really appreciate everyone's comments and expertise.


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## TimMiller (Apr 15, 2008)

I am a fan of LED technology, but i'm not sure how effective it is for lighting up an entire room yet. If they loaded bulbs full of 3W LED's then things would be much better then them loading them up with 1/4 like many manufactureres do.


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## kiilljoy (Apr 15, 2008)

The lamp we looked at, this one, if you want to see provided a nice, bright, even coverage, but like I said, we couldn't get it to dim the way an incandescent light dims. I'm going to use it elsewhere in the theatre where the lamp is hard to change, but only turns one and off. And by the way, I had a bad experience with that particular store. It took more than a month to get the lamp in, and it was very difficult to get in contact with anyone. Eventually, my message got to the right person, and he called me up specifically to explain. Somehow the order had just fallen through the cracks and he told me they were looking into the problem. He also gave me his direct line to contact him if there were problems or if I had future orders. In the for what it's worth category.


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