Loose Contact on NS3 Compact Mod Wheel

[mathofinsects]

Hi--

My mod wheel appears to have a loose contact. With enough vibration or impact, it will stop engaging and return to whatever the "down" state is. I can usually knock on the keyboard just to the left of the wheel and reengage it. But of course it's too late by then...

Does anyone know if this is an easy fix that I could do myself? I'm nervous about pulling the board apart and making any temporary damage permanent. But if it's something as simple a resolder or screw-tightening, I'm happy to do that DYI.

Any experience or advice?

Thanks.

[Hobster]

This is a common problem - there are other threads on this forum with people having the same issue.

The problem is that the 3 wires from the mod wheel are terminated by a female connector which connects with it's male equivalent on the lower-end control panel circuit board.
The connector interface is quite bulky and touches the panel which means that pressure on the top of the panel (e.g. by hand/fingers) in certain places can cause the wheel to misbehave.

The solution that I used - I've since been informed by Nord's distributor in the UK that this is similar to what is carried out if the NS3C is returned for service - is to remove the connectors from the wires and the board and directly solder the wires to the pin remnants left from removing (by snipping) the board connector.
It's not a particularly tricky operation at all (just be sure to mark the leads as they're all red!) if you know one end of a soldering iron from the other, but it may invalidate any warranty if you do it yourself so...
I believe that the latest NS3Cs have this solution already implemented.

Somewhere on this forum there's a post that points to a PDF that explains how to open up a Nord Stage EX 73 for 'Compact Velocity Repair'.
The procedure is pretty much identical for the NS3C except that the NS3C has Torque screws rather than Phillips.

[mathofinsects]

Thank you greatly. I searched but apparently not well. I will look for the pdf; I'm comfortable soldering. I'll report back after surgery.

Thank you once again.

[Hobster]

In case you couldn't find it, here's a copy.
You only need to do the first 4 pages; you don't need to remove the keybed.
Once you have the top panel seperate from the main panel/keybed, you should be able to see what needs to be done to the top panel.

I've also included a (blurry - really old iPod!) photo of the mod once it's done.
The 2 blue & 2 red wires are from the Pitch-Bend Stick; the 3 red wires (with the black pen marks for differentiation) are the Mod Wheel wires.

[baekgaard]

this solution requires more work than is necessary

an alternative, but similar, solution is available; please note that this alternative has been endorsed by Nord

chop the mod wheel plug as shown here, but instead of soldering directly to the panelboard, solder to the bare pins of the header from which the plug was disconnected

this provides the clearance necessary to avoid the problem, but is MUCH faster and easier

please note that it is best practice to chop and resolder one lead at a time to avoid the possibility of mixing them up

bless, pablo

[analogika]

My tech took a look at your recommended solution (thanks for that!), but as the flexing had already loosened the plug connector on the board itself, he immediately opted to desolder that entirely and solder the wires directly to the board. It took about two minutes, all told.

[Hobster]

My solution took all of a couple of minutes...
Marked the leads with 1, 2 & 3 felt-tip pen marks; snipped the connector off the wires; stripped the wires; snipped the connector off the board leaving the old pins in and sticking out a bit; solderered the wires to the pin remnants; job done!
Can't see it being any more work than your solution, Pablo

[mathofinsects]

OK, I took an expeditionary trip into the Nord this evening and saw the weirdly outsized connector. What clumsy engineering from a usually unclumsy company, fixed split points notwithstanding. I play all weekend but will solder this coming week.

Thanks, both suggestions seem workable; I'll probably go right to the board since that's the lowest-profile option.

[pablomastodon]

My board-level tech skills are passable for easy jobs, and understand that others' skills may far outstrip my own. I would not attempt to remove the header from the panelboard with first removing the panelboard from the underside of the upper chassis. Soldering to the header pins is easily done without removing the panelboard.

Anyway, that's my theory. Removing only the plug provides sufficient clearance; more is not needed. Plus, given a choice between beginning to stress/fatigue pads on a circuit board or not doing do, I would usually choose to not do so. But that's just the way my brain thinks. Either way is completely valid.

Bless, Pablo

[mathofinsects]

FWIW, since I opened it up and checked all the contacts, it has worked flawlessly.