control knobs not working right

You say the volume changes a little when you move the knob. Does that change occur during just a part of the motion or across the whole range of the knob? If it is just across a portion of the range, that sounds like a broken or cracked pot. You would need to have the pot replaced.

-Rodan

thanks Rodan - actually I replaced the whole circuit board (including the knobs) already thinking that was the problem.

However, the problem persists - seems to be software related somehow - but seems that this only applies when I have the control knob set to control "volume". When i turn it all the way down there is a slight reduction in volume, when I turn it all the way up - there is a slight increase in volume - not much change through the middle of the dial.

very strange (and this same problem occurs across all 4 control knobs if I set them to control "volume".

Weird issue, seems like the effective range of the potentiometer is reduced. What happens if you assign it to another parameter, like filter cutoff?

good question. I can see now that I tried that, the knobs don't work right for any setting.
When using filter cutoff, moving the knob at all just makes a strange sound (like setting the attack to very low). When the knob is turned all the way up - just produces a high pitch feedback thing. Turning it slightly less than all the way up - down to all the way off - makes hardly any change.

Very strange. Those knobs/pots and circuitry are all brand new and the factory reset didn't fix this either (so it seems that it's not software). So, I really have no ideas on this one.

The master volume knob works just as it should by the way.

cattivo,

You haven't got any weird offset values in the Patch you are using, have you? That could be affecting the range of the control knob.

Look through the Creating a Patch section of the manual. I'll freely admit that I find most of my problems are caused by the TMT and CTRL1-4 tabs of Patch edit.

Also, could you post the Patches or Performances here, then we could try them as well.

Andy

Hey Andy, thanks for your input as well.
I should mention that I've been using this keyboard (and these performances layers - about 50 of them).
I have always used the first control knob set to control volume (assignable) - and it has always worked perfectly until now.

A few weeks ago at a show, all of a sudden, that knob stopped controlling volume correctly and began acting as I've described below. I erroneously thought it was just that knob, ended up replacing the whole circuit board that includes those knobs, and now I still have the original problem.

This problem occurs no matter what performance or patch I set the keyboard to. Including acoustic piano sounds, bass sounds, synth leads - everything seems to do the same.

The only other thing I can think of then, is that one or more of the various circuit boards in your fantom might not be properly connected. If you feel confident, open it up & check all the plugs at the end of the ribbon connectors are fully pushed in. I'd start with the one joining the control knobs to the motherboard.

If that's no good, it's probably a "send it to Roland" job, I'm afraid.

Hope this helps
Andy

yeah, I'm going to try that next. I know the connecters attached to the circuit board I just replaced are in good - but maybe whichever other circuit board it is connecting to has some flaw.

Any experience sending things to Roland for repair? Do they get on things quickly? I'll probably have to rent one in the meantime for shows...

thanks again for your help

Touch wood, none of my Roland gear has ever failed me, apart from some buttons and the internal battery on my old D-5, but i wasn't in a band at the time. Good luck, and let us know how you get on.

SO, I got to the bottom of this issue, but am not sure how to progress, also VERY curious if anyone else has ever seen anything like this. Bare with me on this explanation...

After the above discussion, I took the keyboard to a local reputable repair guy. Before doing so, I removed my SRX-07 expansion board so I could put it in the loaner keyboard (I need some of the sounds from it). The keyboard with the malfunctioning knobs continued to have the same problem already discussed here once I removed the expansion.

Anyway, I got the loaner keyboard, installed my expansion board, and put my sounds backup on the board. SAME PROBLEM as the old keyboard; so I took my expansion board out, and factory-reset the keyboard. The problem (now on the new loaner keyboard) with the knobs persists. None of them function right.

So then, I go a different loaner keyboard. Brought it home, this time did NOT install the expansion board, but I did put my sounds backup on the keyboard. Everything works fine.

So, in conclusion, it seems that somehow my expansion board causes these strange problems with the control knobs AND more strangely, it seems to permanently damage the keyboard, even once it's been removed and factory reset.

Has anyone seen anything like this? Or if someone can do a logic check with me on how I got to that conclusion, please let me know. Thanks as usual for all the help.

I can think of a couple of things that could have caused the problem. In the manual that came with my SRX12 it says:

"Handling the Board
To avoid the risk of damage to internal components that can be caused by static electricity, please carefully observe the following whenever you handle the board.
1 * Before you touch the board, always first grasp a metal object (such as a water pipe), so you are sure that any static electricity you might have been carrying has been discharged.
2 * When handling the board, grasp it only by its edges. Avoid touching any of the electronic components or connectors.

So, perhaps you damaged both units by not grounding yourself before opening the boards? Could the damage have been caused when turning over the board to install card?

I try to be very careful about handling the board, but I guess anything is possible at this point.

Cattivo, I was just trying to do a logic check with you as you requested. I am sure you try to be careful when handling it.

If I were trying to troubleshoot this issue then the first thing I would do is check to see if it is sending the right information. Perhaps turn the knob to 0 and then up to full and back down and record that. Then I would go into the sequencer and check to see if it was sending the full range of information.

Thanks Howard - appreciate the help.
I've done this, and on the affected keyboards, the full range of information is not being sent. Jumbled info is being sent (and changing one knob affects all the other knob) and other random weirdness.

If I didn't know better (from doing factory reset), I would think it was some sort of virus that is making the keyboard's software act erratically. But that has been ruled out - so it really seems to be something with this expansion card causing some sort of circuitry damage.