Could 10cm cables between the MB_6582 mainboard and the CS board be too long?

[borfo]

I'm troubleshooting a few misbehaving switches and LEDs on my recent MB_6582 build - there are still a few switches and LEDs that aren't working.  Could just be bad switches/burnt out LEDs, but before I start desoldering and replacing stuff, I thought I'd ask about maximum cable length between the control surface and the mainboard.  My cables are about 10cm long at this point - is that within acceptable range, or could that cable length be causing issues?  The build guide says something around 4.5cm is "ideal", but is 10cm too long?

Edited June 8, 2017 by borfo

[latigid on]

Should be okay. With a matrix design, you usually get entire rows or columns out rather than a few here and there.

One thing I've noticed, is that the through hole plating is not always the best. For LEDs and switches that don't work, try soldering on both sides of the joint, adding flux if you need to. You have to be careful of melting any plastic components, and also e.g. soldering LED legs one at a time so the alignment stays good.

[borfo]

Thanks - that's helpful.  The cable length thing does have weird effects though - I initially had 20cm cables, and shortening to 10cm fixed a bunch of misbehaving switches and glitchy LEDs.  The few that are still not cooperating are probably bad parts, or as you say, maybe not properly soldered. 

 

I'll start working them over on the weekend.  Normally, I don't mind this kind of troubleshooting stuff with a new synth build, but I'm pretty impatient to get this one fully working so I can make crazy noises with it...  Even in the "almost-fully-working" state it's in now it's pretty amazing.

Edited June 9, 2017 by borfo

[jaytee]

The switches should be easy to test with a multimeter without desoldering. You might need a second human being with hands to help out is all.