Help in tracing down a bug in an electronic musical instrument

Thread Starter

SteveA1

Joined Feb 19, 2021
12
Hi all,

this is my first post here. I am actually not an engineer of any kind, I joined this forum hoping to kindly ask for a professional's opinion over an issue that I am having with a musical instrument, that I am clueless about. I hope it is the right section of the forum and I hope it's OK for a total layman to post such requests in what seems to me like a highly specialised forum to start with. Further disclaimer: I'm not native in English, so please forgive possibly wrong sentences here and there.

The issue is the following: I have recently got a Hammond XK-5, a digital organ, and there something it sometime does, that I believe is a bug, that I am losing my mind trying to see a patter for. It's been totally unpredictable: it goes one month of heavy use without popping up, then it pops up 10 times in two hours, then gone again.

I imagine most people here aren't necessarily familiar with such an instrument, but my hope is that an "expert's eye" could perhaps have a much more informed guess, based on the symptoms shown, as to what could be possibly going on here.

The issue is simple to describe: a popup message that should only appear on the display when I turn a specific knob, appears sometimes on its own upon patch loading. (A "patch" in these kind of electronic keyboards refers to a preset of parameters that constitute a sound -- a saved profile pretty much).

That popup is usually but not always the "Overdrive level bar" that again "should" only appear if I tweak its associated knob. Attached pic 1 shows the main screen as when in normal operation mode, and pic 2 shows the popup as I tweak the knob. I haven't been able to film this bug in real time because it's so random, but luckily a guy on the Internet experiencing the same problem was able to:

<Mod: deleted link>

Now, not only does the popup appear, but it actually changes the Overdrive parameter associated with that patch. I have to recall the patch again to make the value back again as it is as stored in the patch.

As I said, the only "pattern" I could find for this is that it only happens as soon as a patch has been loaded (by whatever means it has been loaded by -- there are several). If it doesn't happen a second after this, then it doesn't happen.

The only few responses I was able to find online are from people who say "I am getting this bug too", but being this instrument an extremely niche (and extremely expensive!) one, there isn't a community of any kind around it that could provide insights.

Now what I am wondering is the following:

1) first of all, as a layman I'd strongly suspect it's not hardware related but a glitch in the firmware. Does it look the same way to you?

1a) Sure enough the knobs aren't faulty (any of them)

2) Could this possibly be caused by some "overbuffering", if this makes sense, of certain data that until the keyboard hasn't refreshed, makes the bug appear?

3) The firmware I am running (this is the link) is the latest one provided by the manufacturer: the idea of trying looking inside it and embark the enterprise of trying fixing it... is feasible or I should rather forget about it?

This was long to read and I thank very much all of you who took the time to read. :)
Any insight would be highly appreciated.
Steve
 

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drc_567

Joined Dec 29, 2008
1,107
... Taking a shot in the dark, so to speak, occasionally humidity, that is atmospheric moisture, will infiltrate rotary knobs and adjustments. A possible generic repair for this problem is to try spraying electrical contact cleaner in and around the suspected cause of the glitch. You should be able to obtain a spray can of 'Plastic Safe' electronic contact cleaner at an electronic supply store, or maybe online. Then see if you can manage to spray the vicinity of the pop-up causing knob, which was mentioned previously. It may be necessary to access a service panel or cover plate in order to spray the contact cleaner on the specific area of the knob component that is actually causing the problem.
So try using the contact cleaner spray, either external!y, or if necessary, from an internal application.
Try rotating the suspect knob while spraying the contact cleaner, for better spray penetration. Then allow some time for the cleaner spray to dry and evaporate.
... If no success, update the situation here on the forum.
 
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Thread Starter

SteveA1

Joined Feb 19, 2021
12
Thanks for the hint, but it can't be the knob itself for a variety of reasons:
1) the popup *only* appears, when it does, immediately after a patch has been recalled, otherwise it never appears (this in itself should be enough to rule it out);
2) it's usually the OD knob but occasionally the Effects popup comes out as well;
3) other people have this exact same issue: with all the knobs and buttons, why always the OD / Effects / Reverb?
4) the knob(s) itself work perfectly in their own.

I am a layman in electronics but this far I am confident to go: it's not the knob.

By the way a Facebook page I linked to had a clip of somebody who was able to catch the glitch on camera: that link was removed by a forum admin, so I don't know how it can be re-posted without violating the forum rules...
 

drc_567

Joined Dec 29, 2008
1,107
... Ok ... another generic approach to the problem is to take a look at the related wiring in the service compartment. If there are any wires that are not stretched or taut, see if it is possible to gently bundle or collect together any excessively loose wiring, using a wire tie or other convenient means. The idea is to eliminate any 'crosstalk' between wires that may be the source of the problem.
... Just make sure that the organ is unplugged from the mains power, and that you are careful not to stretch any wires in a manner that would break a connection.
 

Thread Starter

SteveA1

Joined Feb 19, 2021
12
The keyboard is new and well under warranty, so I am not opening it. Especially considering its cost! But I guess most of the points made above hold for any wire-related issue as well: it's too systematically "after a patch loading" that it has to be more complex than bad wiring.

Something that I didn't mention before is that the issue seems to show up more after some heavy parameters editing. Now to clear any potential misunderstanding beforehand: there is no option in the menu that would cause the popup to appear like that. Also, as I said the popup doesn't just "appear": it's the values that get altered upon patch loading and then the popup appears as a consequence.

This keyboard "remembers" its last state before switching off, and I am wondering whether some of this data gets accumulated in some "queue" that, if gets too long, starts producing issues and causes the patch loading system to behave strangely. Some sort of buffer or so...
 

drc_567

Joined Dec 29, 2008
1,107
Have you tried 'resetting' the organ, that is just turning the power off and unplugging it from the mains
power for a few seconds? ... It could be that some sort of voltage excursion, due to an electrical storm or mains power deviation has created a malfunction.
 

Thread Starter

SteveA1

Joined Feb 19, 2021
12
It's difficult to say if a reboot "refreshes" something or not, because the pop up stays there for a second or so without really causing any malfunction, so it's not that I really need to reboot the machine to make it work again.

What I can say though is that sometimes it has happened soon after I turned it on, so I'm guessing this means this "buffer" doesn't get emptied on power off.

I use an online UPS, and I power up a few other keyboards from that UPS, no issue whatsoever.

Clearly this is something about the firmware, but what is it... This is driving me crazy because I can't seem to find a logic in it. It's not "after a specific patch has been recalled", or something like this. It seems to popup randomly during any patch loading.

Is the idea of looking into the firmware as provided by the manifacturer too wacky?
 

bertus

Joined Apr 5, 2008
21,361
Hello,

Did you try to initialize the system (from the manual):
XK-51. INITIALIZATION
Do the followings to return all the paramater values to the factory settings.
A. Turn OFF the power of the XK-5.
B. Holding down [RECORD] button, turn on the power.
C. Keep Pressing the [RECORD] button until the "Loading Default...." appears on the display.
D. Initialization is completed when the normal PLAY mode appears on the display.

2. HOW TO CHECK THE SOFTWARE VERSION
You can check the software version number inside of the XK-5 by the following procedures.
A. Turn ON the power of the XK-5.
B. Press the [MENU/EXIT] button while the mode is the normal PLAY, and switch to the MENU mode. Then select Page F by pressing [PAGE ] button(press five times).
C. Press [RIGHT > ] button and move the cursor to "SYSTEM" and press [ENTER] button. "POWER AUTO OFF" setting screen appears on the display.
D. Press the [PAGE ] button three times, and display the MAIN version.
E. Next touch [ > ] button and display the WAVE INFO (the sound waveform information) version.
F. Next touch [ > ] button and display the DSP0 Program Version.
G. Next touch [ > ] button and display the DSP1 Program Version.
H. Next touch [ > ] button and display the FPATCH (default data of the factory setting) version.I. Next touch [ > ] button and display the SUB (key scan) version.
J. Next touch [ > ] button and display the PANEL (switch scan) version.

Bertus
 

Thread Starter

SteveA1

Joined Feb 19, 2021
12
Thanks bertus, I did do the procedure to reset to factory values (it can be done from within the menu as well, no need to power it up while pressing "Record" -- although it obviously works too), but as I wrote before it's hard to tell this fixes the problem or not: it happens so scarcely that I don't know if a factory reset actually does something or not.

I know every ins and outs of the menu and I am running the latest 3.3 firmware. Maybe I went too far saying I am a layman in electronics! Just kidding:D:rolleyes:

EDIT: since I can't post links in the forum, if you google "xk5 users is this normal", then the first video from Facebook that appears (below the first YouTube results) should be the one I originally linked to. Here the issue can be seen realtime.
 
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sagor

Joined Mar 10, 2019
439
I would follow the power down reset proceedure, not the one internal in the menu. There could be a difference between "hard reset" and a "soft reset" between those two methods. A soft reset may keep some hidden user parameters, a hard reset will clear everything (usually).
 

Jon Hoover

Joined Oct 10, 2019
33
Another thing to consider is the patch itself. If this is a factory patch, then it should behave. If this is a patch that was found online or written by someone else and loaded into the keyboard, then it could be buggy and misbehave. You also mentioned that this happens to a patch(s) after heavy editing. There may be an "undo" buffer that gets full of all the edits and it doesn't clean itself out properly. Once all editing is done, save the patch and power cycle the keyboard to clear all buffers and see if that helps. It's a pain in the neck, but it may work. If all else fails, contact the manufacturer and inform them of the issues you are experiencing and see if they might have a solution. Good luck!
 

Thread Starter

SteveA1

Joined Feb 19, 2021
12
Thanks Jon. Yes I too thought it could have something to do with the patch itself, or maybe a specific parameter that's active in certain patches. But I couldn't find a link there. It has happened both with custom patches and with factory patches, and not always with the same ones. There doesn't seem to be any connection between which patch is going to do it and which isn't, and this is way it's frustrating to find a pattern. The fact that it happens very rarely is another major reason for why I fail to track it down.

By the way by "heavy editing" I didn't necessarily mean "to a patch". Some parameters are per-patch, some are per bank, some are global, some are per-group of settings, and some other can be made either patch-specific or global, so it's a bit more nuanced. By "editing" I meant that I just fiddled with a lot of those parameters, and often without even saving.

As for rebooting after each saving, this isn't the point as I always power it off after use, and this would by definition make it impossible for the bug to popup soon after a reboot. But it has. Other times, it can stay on for hours with me changing presets all the time and nothing at all happens.

I already sent an email to Hammond-Suzuki but they didn't reply back, as I had imagined. I hope they are working on a firmware update but wouldn't be too optimistic about that either.

Is trying to look at the firmware files itself to try and see what could be wrong with them an out of the question idea?
 
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Jon Hoover

Joined Oct 10, 2019
33
I wouldn't really have any idea about that. I'm not really a programmer but I have used enough equipment that has it's own "personality" quirks that have required me to jump thru hoops to get it to perform as expected. I was just forwarding a few of the things I have tried in the past to make things behave when they didn't want to. Worst case, ask for your money back if they can't fix it during the warranty period. I know that's not what you want to hear but sometimes..... :)
 

Thread Starter

SteveA1

Joined Feb 19, 2021
12
Thanks Jon. Definitely not worth returning it, as it's an amazing instrument in all respects! If I won't be able to solve this, I guess I'll just have to live with this "quirk".

As for the firmware inspection, I'll ask in the programmer section.
 

Thread Starter

SteveA1

Joined Feb 19, 2021
12
Hi everyone,

as a layman in programming, I am wondering how feasible / easy (?) it would be to look into the firmware files of a device to try find a bug the device shows -- and possibly fix it, but even simply finding its cause would be a big achievement.

The device in question is a Hammond XK-5, a digital organ (keyboard). The official latest firmware is this.

I attach the schematics I found to this thread.

I have no idea how actually feasible all of the above is... as i said I am not a programmer, so if someone could give me a hint... much appreciated. ;)

Thank you
 

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Thread Starter

SteveA1

Joined Feb 19, 2021
12
I posted this in the "embedded / programming" section, thinking it was the right one for such a thing, but it has been moved back here...
 

ericgibbs

Joined Jan 29, 2010
12,883
hi Steve,
The two Threads have been merged as they are both for the same Topic, ie: a debug and repair of the same piece of equipment.

E.
 

Thread Starter

SteveA1

Joined Feb 19, 2021
12
OK thanks for clarifying. I would have thought that looking into a firmware code had more to do with programming, but not a big deal ;)
 

ericgibbs

Joined Jan 29, 2010
12,883
hi Steve,
Regarding Technical Repairs, we often see common faults reported which are posted for the same piece of equipment.
Others with the same equipment problem often carry out web searches for solutions, which can direct them towards AAC.

Over time, your thread could build into a useful database.

If you look thru the Tech Repair Forum, you will see that some threads have been active for a long time.

E

PS: example.
https://forum.allaboutcircuits.com/...oblem-speakers-headphones.140229/post-1180136
 
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