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Thread

Emax II E3 note sticking

2010-12-02 by mud_plugga

While playing with my 4Mb 2212 today, I noticed that the E3 note is sticking and will not turn off.  It was working fine yesterday.....

I had a quick look and re-cleaned the contact spring, but that has done nothing.

What is going to be the problem here, or how can I go about finding what the problem is?  I have the Emax II diagnostics guide, but that did not provide anything useful.

(It is only the one key on the whole keyboard - all others are still working).

I was hoping it would be something easy, as I have no real electronics skills to play with this myself, and being in Sydney Australia I'm not sure who/where in this part of the world to take it to for repair.

Any help/ideas gratefully received!

Steve

Re: Emax II E3 note sticking

2010-12-02 by Niklas N

It's probably a hardware problem.

It sounds like it could be the key spring, as you mention.
Have you checked if it is located centrally between the two copper wires? Is it damaged in any way and may have fallen off when mounted back the keyboard?

If not I'd should trie to clean the springs and the circuit which they are connected to with electronics cleaning spray, if it would be corrosion.

cheers
niklas

--- In emax@yahoogroups.com, "mud_plugga" <steve.limbrick@...> wrote:

Show quoted textHide quoted text

>
> While playing with my 4Mb 2212 today, I noticed that the E3 note is sticking and will not turn off.  It was working fine yesterday.....
> 
> I had a quick look and re-cleaned the contact spring, but that has done nothing.
> 
> What is going to be the problem here, or how can I go about finding what the problem is?  I have the Emax II diagnostics guide, but that did not provide anything useful.
> 
> (It is only the one key on the whole keyboard - all others are still working).
> 
> I was hoping it would be something easy, as I have no real electronics skills to play with this myself, and being in Sydney Australia I'm not sure who/where in this part of the world to take it to for repair.
> 
> Any help/ideas gratefully received!
> 
> Steve
>

Re: Emax II E3 note sticking

2010-12-02 by emax_dx5

You can do a Midi out test (using the MIDI SCOPE or any external midi device) just to confirm that there is not sent a NOTE OFF command

Assuming the spring is doing his job, that is almost sure a faulty trace on the keyboard PCB. You will need to remove the keyboard printed circuit board and check the traces involved on that key. Sure the Key Off trace has some problem (Maybe a cold solder or so).

It is a common issue. I had two emaxes with that same problem. In one of them I had to re build three traces showing corrosion. In another, a whole octave started to fail. Re building traces fixed it all.

Re: Emax II E3 note sticking

2010-12-02 by mud_plugga

Thanks for the reply.

The spring hadn't fallen off - I last cleaned it months ago and it has been working fine up until yesterday (I then opened the keyboard up again today to see what I could find and the spring was mounted OK, though I did reclean it again at that time).  The note does not come on as stuck from the moment the keyboard is fired up, it is only once I have played the note.

As for cleaning the circuit, where do I find any schematics to see what board and which circuits I should be looking at?  This - including DX5s suggestion that a rebuild of circuits may be required - is starting to sound like something I'm not comfortable playing around with.......  What sort of specialist would do such work?

Steve

--- In emax@yahoogroups.com, "Niklas N" <niklas627@...> wrote:

Show quoted textHide quoted text

>
> It's probably a hardware problem.
> 
> It sounds like it could be the key spring, as you mention.
> Have you checked if it is located centrally between the two copper wires? Is it damaged in any way and may have fallen off when mounted back the keyboard?
> 
> If not I'd should trie to clean the springs and the circuit which they are connected to with electronics cleaning spray, if it would be corrosion.
> 
> cheers
> niklas
> 
> --- In emax@yahoogroups.com, "mud_plugga" <steve.limbrick@> wrote:
> >
> > While playing with my 4Mb 2212 today, I noticed that the E3 note is sticking and will not turn off.  It was working fine yesterday.....
> > 
> > I had a quick look and re-cleaned the contact spring, but that has done nothing.
> > 
> > What is going to be the problem here, or how can I go about finding what the problem is?  I have the Emax II diagnostics guide, but that did not provide anything useful.
> > 
> > (It is only the one key on the whole keyboard - all others are still working).
> > 
> > I was hoping it would be something easy, as I have no real electronics skills to play with this myself, and being in Sydney Australia I'm not sure who/where in this part of the world to take it to for repair.
> > 
> > Any help/ideas gratefully received!
> > 
> > Steve
> >
>

Re: Emax II E3 note sticking

2010-12-02 by mud_plugga

DX5,

Is checking traces - and repairing them - an easy task for a non-solderer (or someone with no electronics skills)?  I've built PCs before but that was just installing and connecting the right components, not something this technical.  Are there schematics or anything for the relevant boards to see which trace I'm needing to look for, or is it pretty obvious which trace is for which key once I start looking at the boards?

(Excuse my ignorance with all this).

Steve

--- In emax@yahoogroups.com, "emax_dx5" <cadena100rb@...> wrote:

Show quoted textHide quoted text

>
> You can do a Midi out test (using the MIDI SCOPE or any external midi device) just to confirm that there is not sent a NOTE OFF command
> 
> Assuming the spring is doing his job, that is almost sure a faulty trace on the keyboard PCB. You will need to remove the keyboard printed circuit board and check the traces involved on that key. Sure the Key Off trace has some problem (Maybe a cold solder or so).
> 
> It is a common issue. I had two emaxes with that same problem. In one of them I had to re build three traces showing corrosion. In another, a whole octave started to fail. Re building traces fixed it all.
>

Re: Emax II E3 note sticking

2010-12-06 by mud_plugga

Just a quick update.  After leaving the keyboard for a few days while I was away, I returned to find it all working properly again!

That said, I have found a guy in Sydney (thanks to Tristan for the link!) who was the official E-mu techician/repairer here in the 80s/90s - amongst his many musical projects - and he has a workshop still doing synth repairs.  As such, I figured it was worth him  checking it out, if not for anything more than a really good clean and EL foil replacement.  Will see what he finds over the Christmas period.....

For anyone interested the repairer is at www.synthrepairs.com.

Regards,

Steve

--- In emax@yahoogroups.com, "mud_plugga" <steve.limbrick@...> wrote:

Show quoted textHide quoted text

>
> DX5,
> 
> Is checking traces - and repairing them - an easy task for a non-solderer (or someone with no electronics skills)?  I've built PCs before but that was just installing and connecting the right components, not something this technical.  Are there schematics or anything for the relevant boards to see which trace I'm needing to look for, or is it pretty obvious which trace is for which key once I start looking at the boards?
> 
> (Excuse my ignorance with all this).
> 
> Steve
> 
> --- In emax@yahoogroups.com, "emax_dx5" <cadena100rb@> wrote:
> >
> > You can do a Midi out test (using the MIDI SCOPE or any external midi device) just to confirm that there is not sent a NOTE OFF command
> > 
> > Assuming the spring is doing his job, that is almost sure a faulty trace on the keyboard PCB. You will need to remove the keyboard printed circuit board and check the traces involved on that key. Sure the Key Off trace has some problem (Maybe a cold solder or so).
> > 
> > It is a common issue. I had two emaxes with that same problem. In one of them I had to re build three traces showing corrosion. In another, a whole octave started to fail. Re building traces fixed it all.
> >
>