NS3 Compact Strange Issue - lower 8 keys not working

[davecad]

Hoping for any insight from the hive mind....

Stage 3 Compact, OS 2.62

I've had this board for a few years and love it - except for the repairs! Had a chip replaced a couple years back by a real professional repair person, and honestly don't remember the exact issue . . . but then the device would occasionally encounter the power up issue described here:

viewtopic.php?t=26065

So, I decided to replace the main board at $1200+ USD, in October 2024 (now out of warranty of course). All has been well, until the current issues.

To wit: The lower 8 keys (E through B) intermittently fail for the piano and synth engines. They seem to consistently work for the Organ engine, without failure. No rhyme or reason that I can find - sometimes while I'm actively playing they'll stop working, and then suddenly work again.

At first I thought it was maybe a key bed or contact strip issue until I tested the synth/organ/piano separately. I did read someone else's suggested resolution as a ribbon cable but I don't know if that would be unique to each engine?

Notably, when the issue is happening, there is no MIDI output from those 8 keys either, but everything works hunky dory from external MIDI controllers, with no strange behavior, so I'm fortunately able to make do, but I fear this is a cascading failure scenario. I really like the board but I'm $1600 in beyond the original purchase already and not happy about problems continuing following the main board replacement.

I mean maybe worth a $20 purchase for a ribbon cable, to see if there's any improvement, but I am skeptical. As I'm typing I realized I didn't try a factory reset yet but will do that soon too.

Has anyone encountered anything like this that could offer any advice? Buying an NS4 is not in the budget at the moment - - plus if I tried to sell or trade the current unit seems unlikely that anyone would pay much given that current problem.

I appreciate all the great advice I've received over the years from this forum. Thank you for reading my verbose complaint and for any help!

[Bacon]

The organ section gets triggered by a higher sensor than the piano and synth sections to get closer to the feel of a real organ. Maybe the high sensor is still working while the one at the bottom of the key travel is not working, and it's only the bottom one sending MIDI.

[maxpiano]

Could a problem at flat cable level or keyboard scan board (like a diode of the scan matrix broken, namely the one that selects the low trigger of those 8 notes).

[cphollis]

Screams "loose cable connector" to me.

[maxpiano]

Screams "loose cable connector" to me.

Could also be, when I wrote that problem could at "flat cable" level I meant all elements of that link, including connectors (so it is good you added that explicitly)