Just wanted to say a big thanks for this article. Worked a treat.

Reference for anyone else who might encounter this particular problem:

Fader 5 was only making it half way up on calibration test. If you moved it up and down for a while and then turned the unit on it would pass calibration, but if you tried it again without this little ritual, it would again only make it about half way up.

In the end, it looks like the issue was possibly the rubber o-ring at the top of the slide bar. It was sticking to the fader guide and getting dropped off at random places along the slide. Then when the fader moved up again it was encountering a small amount of extra resistance from the o-ring, which I guess confused it into thinking it had hit the top of the guide. I blew air on, greased, and oiled everything in sight just to make sure there were no other resistance points, and made sure the o-ring was greased nice and good so it stayed stuck at the top of the slide instead of stuck to the fader.

It appears to have fixed my problem; fader 5 is so far working fine. It was such a stupid little issue, I thought I’d post it in case it solved any hitherto unexplainable fader problems.

Cheers.

0) desolder the optical sensor first of all
solder it back on

My solution was:

1) move the fader towards the end (away from the motor)
2) lock it with an elastic rope or something similar
3) do not wind the green string around the copper guide thingys at the end
4) do the rope in the silvercoloured thing which moves (check the knut)
5) lock the silver coloured thing which moves with a piece of a tie-rap
6) wind it up (this is the hardest part) 7 times. BEGIN not at the lowest point possible on the silver coloured thing which moves. Just one step higher please!
7) Last step is to put the green string on the copper coloured guide thingys

I experienced also a fader malfunction. I opened it with the description and the string came lose; it was a big mess. I can proudly say that I fixed it with some patience!! But now the fader moves not so smooth anymore… :( what to do?

I had the same problem when I tried to fix one of my stuck fader. I tried to lubricate the rails using spray which was a HUGH mistake.
At the end of the fader motor is a little disk with lots of tiny breakouts. This disk is used to measure the fader position. I think by using spray I messed up these tiny holes and the sensor. This is how a managed to get it fixed.

- Disassemble the fader like descriped above.
- spray the disk and the senors with compressed air
- test the fader
- if it still doesnt work whipe the disk very gently with a lint free or microfiber cloth. You might need to do this several time.

Hope this helps

Martin