Hi Guys,
a few months ago my top C key lost its touch sensitivity on my NE2 73, and so when played it came out at maximum volume. a bit of a disaster, but i rarely play up that high with rhodes/piano sounds so i just got over it (its fine on organ of course, where there's no velocity to worry about)
Last week though, disaster struck, when my B below middle C did the same thing, though its worse than the high key, as it sometimes doesn't sound at all, and other times comes out at full volume. (again, it always sounds fine when using organ)...

So being a key that i use a lot, i decided i better take the beast apart and give it a clean.
I went right down to lifting the rubber pads from beneath the keybed, cleaning the contacts with alcohol, and then putting it all back together.
That didn't help, alas.
Next i upgraded the OS to version 3 from 2.3. Strangely enough that seemed to to fix it, for a little while, but a few hard strikes while playing the key and the problem returned....Each time i loaded on a new patch with the Nord Electro Tool, (the upgrade wiped my ROM) it seemed to fix it for a little while, but then returned again.

I'm a bit stumped. The fixing, and then subsequent return seems to spell that its a software problem, but i'm a little dubious.

Has anyone any suggestions please!?

(maybe replacing the lower section of the keybed?...and if so, where would i find the parts? (it is a Fatar 76 key keybed isn't it?)

Thanks in advance!

Still sounds like dirty contacts. The fact that you've cleaned it would put lie to that, but still...

Was it dusty dirty inside? Is it (are they) always the same key(s)?

I once had a board do this (in the 90's - an Alesis Quadrasynth). ROM was scrambled, board was doing weird stuff, sounds were scrambled...I sent the board back to Alesis, and they sent me a new one. Went to a gig a few weeks later and same thing, different board.
I finally figured out that I had run some coax for my 2M Ham Radio's antenna underneath the carpet in the cargo area (CRX). The EM field from the coax was right where the Alesis' brain was when transporting. When I transmitted on the radio it scrambled the keyboard's brain. Duh. I'm sure this isn't YOUR problem, but it's an amusing anecdote while you're wracking your brains.

Well indeed, it stinks of dirty contacts in some respects...especially when it happened first, the B key stopped working, so i gave the whole keyboard a bit of a shake and it came back to life (albeit without velocity)...but since then it works for a period after power off/on (sometimes) and then goes nuts after i hit the key hard.

Strange thing was i expected the keybed to be fairly dirty, but it was surprisingly clean in there!




Alas, (or maybe not, as it sounds like a tricky solution to figure out!) i don't think its an EM field!

I doubt the keyboard has electrical contacts. Most use Hall-effect switches or optical ones.

Hall-effect switches are those ones with the little magnets in rubber, which we see on many handheld devices and also in volume pedals. They use some kind of magnetic magic with semiconductors. They're not very sensitive to dirt.

Optical ones might be, but I doubt that's what's in the E2.

In any case, each note has two sensors, top and bottom. On E2 in organ mode, only the top sensor is used. Otherwise, it's velocity-sensitive, using the time between the two sensors to determine the velocity, and triggering on the bottom one.

However, if the bottom sensor was consistently failing, I'd expect NO note, rather than a note with incorrect velocity.

It may also be that in organ mode, if it sees only the bottom sensor, it triggers the note anyway (rather than using just the top sensor as it normally does).

I suggest you put it in organ mode and see how far down you have to press keys to get them to play. Find a way to measure it. Then do it on the bum keys and see if there's a difference, or if it's inconsistent. If so, it's the top sensor that's your problem.

If not, we may not have learned much for sure. I'd be leaning more to the bottom sensor, but only if I've made some correct guesses.

Oh, btw, I thought I'd add this.

A couple of times I've had a flaky pedal with Hall-effect sensors, and tried to take them apart and put them back together.

So far, I'm batting 0.

Maybe they were already hosed before I tried, or maybe they're real sensitive about being put together just so. But, since then, I've avoided messing with the sensors themselves.

My MR76 is dying (keyweights breaking off). When it gets to the point of being garbage, I'll probably do some experimentation. It has loads of those sensors.

Hi,
I had a similar problem with my E2-73 awhile back. This is part of the post I put up. You may know this stuff already but just in case...

When you put it back together take note to line everything up carefully. There are little rubber pins which line up to holes in the circuit board.
When you put the screws back in start at one end and work your way across. Taking care not to over torque them. Be real careful when you put these back in. If you strip them out you are literally screwed. You will have to find a slightly larger screw to replace it with, and hope you don't crack the post you are putting the screw in. If these are not tight enough it can cause problems like the ones you describe.

If the problem is not in the alignment of the keys. Then it sounds like an intermittent connection somewhere. This could be a loose connector or a cracked circuit board trace.

Re-seat all the connectors just to be sure.

The new lead free solders used today are slightly more brittle than the old school stuff, meaning they are more prone to failures caused by vibration shock ect...

Use a magnifying glass to inspect all the solder joints and traces around the suspect keys. Sometimes re flowing the solder around the suspect keys will fix this.

One way to find a cracked trace is to use a pencil ( eraser end ) to gently push on the circuit board while the unit is powered up. Observing when it works or stops working.

Best of Luck To Ya
Karl

This thread:

http://forums.musicplayer.com/ubbthreads.php/ubb/showflat/Number/2115584/Searchpage/2/Main/148906/Words/full+volume/Search/true/Re_One_Key_at_Full_Velocity_He#Post2115584

Covered the repair to a similar dirty contact problem in great details. When I performed this cleaning on my Electro, my similar problems were completely resolved.

Good luck!

--Dave

Thanks Guys - there's some great suggestions there. I'll be back with my poor little sick nord after the weekend, so will give it another go then.
I'll report back!