Mixer Restoration Project

[DangerMouse]

I'm restoring a Soundcraft LX7 that I picked up cheep a while ago. It had been living in a club and there was a fair bit of gunk that had worked its way down onto the circuit boards during its time there.

 

I'm trying to bring it back somewhere near to its former glory, and its going to live in my studio, and I'd like to know about various cleaning products to use in the restoration.

1. For the switches - Servisol Super 10 Switch cleaning lubricant (already got this)
   
2. For the pots - dunno - I think that if I use the Super 10 on this then it could wreck the lubrication already inside them? is this the only damage it could do, or could it completely wreck the pots?
   
3. For the faders - same as for the pots?
   
4. For the circuit board itself? - I've got some Servisol Foam Cleanser 30 (Anti-static foaming cleanser). Is this safe to use on the board or should I go for the Isopropyl alcohol or something else?
   

Thought it best to ask questions before spraying the internal workings with the wrong thing. Any advice would be greatly appreaciated. I'm wandering in the dark on this one.

 

Thanks,

[Pete Alcock]

Hi DM,

 

First, before reaching for the aerosols, I'd do a full functional check on the desk. If everything is actually working but it just looks cruddy, restrict your cleasing to everything above the panel. The LX7 is not an easy desk to dismantle, and even harder to get back together properly. If you start spraying foam cleanser all over the boards, I can almost guarantee that something will be noisy or not work afterwards.

 

If everything works OK, take all the knobs off and the switch caps, and put them in a seive with a saucer on. Then put them in the dishwasher. They'll come out perfect.

 

Next, use Servisol foam cleanser to clean all over the panel. Try not to get too much through the fader slots.

 

If you have any scratchy faders, a little switch cleaner may help, but I find it's rarely a permanent fix. The faders can be replaced but you need to get the (large) pcb's out and it's a delicate job with solder wick. You shouldn't find any crackly pots as the ones used seem to be good quality. I've never had this on any of my soundcraft desks.

 

This is a link to one I did a while ago: Earlier post about LX7

 

"Minimally invasive" is definitely the way to go with an LX7. They weren't designed with a service engineer in mind (unlike a Neve or SSL for example).

 

Good luck with the project. If you need any schematics, I have a full set.

 

Pete.

[KevinE]

The best fader lubricant by far is CAIG spray, but used very sparingly as it's quite greasy and a good insulator if used to excess.

 

But dont use it to try and bodge a worn fader...its ok for cleaning a dirty one. If the faders are crackly 'cos they're worn due to much use, then replacement is the only sure-fire way.

 

http://www.caig.com/

[palantir]

Use switch cleaner with great caution:

I used it to free up a sticky fader on my Yamaha 2031 GEQ & it made it feel very loose & "dry" compared to the nice slick feel of the rest. It has regained some "slickness" over time, tho'.

 

Pete

[KevinE]

The problem with any old switch cleaner is that it washes away the special lubricant that makes pro faders feel so silky. There's nothing worse (within reason) than a 'scratchy' or 'gritty' feeling fader. The CAIG stuff replaces the original lube at the same time and they do feel good afterwards..but heed what I and others have said about worn out tracks.

 

Some basic switch cleaners can also degrade certain plastics and even 'weld' them together..v. embarrassing.

[DangerMouse]

Pete, thanks a lot for the reply. I knew I'd seen someone else who'd restored and LX7 on here once but couldn't find the post.

 

I have already taken the desk apart, but there were a few electrical problems with it that need sorting once inside. Couple of dodgy LED's, a few noisy switches and one of the faders. The only major problem on it is Aux 4 is dodgy - works on some channels, not on others...dunno whats going on there but hopefull Occam's razor applies.

 

My plan was to give it a good clean inside, spray some switches (which in hindsight can be done from outside). Then reassemble and taken note of things that don't work (if I can get it to work at all again) and go from there. Probably not the best idea in hindsight, but it has meant that that I've given the case a damn good clean! Anyways, can't turn back time!

 

Guess I will need schematics in order to fix this - will PM you about that.