electronics, repairs, service manuals and datasheets discussion community for the repairs professionals and technicians
FAQSearchMembersGroupsRegisterProfilePM'sLogin/Out
Sourcing pots for E-MU Xboard keyboard
Goto page Previous  1, 2, 3  Next
 
Post new topic   Reply to topic    Electronic equipment repair and service manual search discussion Forum Index -> Equipment Repairs
View previous topic :: View next topic  
Author Message
jts1957



Joined: 24 Nov 2008
Posts: 2472
Location: Far, Far Away

PostPosted: Tue Feb 16, 2010 2:50 am    Post subject: Reply with quote

All six items are identified on the board as "R's." Wouldn't "S" or "SW" be more appropriate for switches?
Yes cleaner (cleaner/lubricant) will clean pots and switches, but it usually makes their operation looser not stiffer.
Small short burst once or twice shouldn't disperse ALL dampening compound (if uses any). Confused
_________________
You're over there, I'm over here.
Back to top
View user's profile Send private message
sisbrains



Joined: 14 Feb 2010
Posts: 15

PostPosted: Tue Feb 16, 2010 6:56 pm    Post subject: Reply with quote

vtech wrote:
In looking at your first set of pictures, apparently those are in fact rotary encoders which are completely different than standard potentiometers. (the microcontroller Atmega48 (U1) to the right of the controls is a solid proof) While tarnish can still build up inside the controls and cause erattic operation, there is a possibilty that you may have a digital problem?


Hi Vtech, thanks for looking at them for me. The problem I have with the encoder is that when I turn the dial from zero, nothing happens until I reach about one third of the way round, then it starts counting up to 127 as normal. It isn't the end of the world, it's just that I can't tell the approximate value of the no. 2 dial by looking at it, because of this.
I have just bought some 'contact cleaner' from Ebay, it was only £1.99 for a can, so I hope it's okay.



vtech wrote:

Ofcourse as jts1957 suggested you may want to spray clean it first. Keep in mind that spray-cleaning might cause a somewhat stiffer operation if you happen to have a very smooth-operated potentiometer--so don't spray all of them. As it cleans the contacts, it will also clean out any dampening fluid used for smooth pot operation.


I will start off with just a tiny spray, turn it a few times, and see if that improves things. Thanks for warning me.

vtech wrote:

On your second picture, while not an encoder, it looks to be similar in operation to a Joystick potentiometer. Meaning that the full 10k ohms is linear and accomplished within 90 degrees instead of a standard ~ 300 degrees pot.


Does that seem normal for a keyboard mod wheel? I'm sure it used to go from 0 to 127 over the entire range of the wheel's movement, it wasn't 127 at halfway.
Back to top
View user's profile Send private message
sisbrains



Joined: 14 Feb 2010
Posts: 15

PostPosted: Wed Feb 17, 2010 3:24 pm    Post subject: Reply with quote

I've cleaned both of them with some 'contact cleaner', turned the dials many times, but with no effect. I gave them each one very short burst, turned the dial about ten times, nothing happened, gave them another very short burst (it comes out of the can like a rocket, so they'll be well covered), but no luck.

I think it might be a digital problem as you say, Vtech. I bought the XBoard as a 'refurbished' item off Ebay, the guy selling them used to sell loads of refurbished Creative items every day, and I got my XBoard 61 for about £70 total, which was a hell of a bargain. Is it worth me looking over the circuit board for cold solder joints, as that's the only thing I have any chance at all of being able to fix, or is it highly unlikely to be that which is causing the problem?

The mod wheel is the only thing that's a real problem, I can live with the MIDI CC knob not working correctly, at least it's working! But the mod wheel is unusable, and it means I can't control my synths properly.
Back to top
View user's profile Send private message
sisbrains



Joined: 14 Feb 2010
Posts: 15

PostPosted: Wed Feb 17, 2010 6:10 pm    Post subject: Reply with quote

I've e-mailed E-MU support, to see if they can give me an idea of how much it would cost to fix it. I am hoping I can send them just the circuit board, not the entire keyboard!
Back to top
View user's profile Send private message
sisbrains



Joined: 14 Feb 2010
Posts: 15

PostPosted: Wed Feb 17, 2010 10:47 pm    Post subject: Reply with quote

E-MU support say they no longer support the XBoard range as they no longer produce them, and it isn't viable to repair them. (Or words to that effect.)

If any of you have any other suggestions, I would be very grateful.
Back to top
View user's profile Send private message
sisbrains



Joined: 14 Feb 2010
Posts: 15

PostPosted: Sat Feb 20, 2010 1:40 pm    Post subject: Reply with quote

I tried swapping the leads from the 'Slide' socket, with the 'Modu' socket (the mod wheel (obviously!) goes into the 'Modu' socket normally, and the Data Entry slider goes into the 'Slide' socket), and tested the output with MIDI-OX, and the mod wheel pot itself is working fine, it gave out data correctly. The Data Entry slider then exhibited exactly the same output problem as the mod wheel had been showing before - jumping straight from 0 to 127, the moment I moved it a tiny amount.
So it's definitely not the pot, probably not the encoder either (for MIDI CC on knob no.2), and probably much worse, as the 'Modu' socket itself leads to wherever the real problem is. I know that one of the tracks from it goes to the microcontroller that vtech talked about.

I have carefully scanned the whole of the board for any cold solder joints (I don't know if this is likely) but couldn't see any.
Back to top
View user's profile Send private message
sisbrains



Joined: 14 Feb 2010
Posts: 15

PostPosted: Sat Feb 20, 2010 2:14 pm    Post subject: Reply with quote

And I should say, to anybody else who experiences this sort of problem, the first thing to try is swapping the leads, not trying to clean the components.
Back to top
View user's profile Send private message
vtech



Joined: 08 May 2006
Posts: 1264
Location: USA

PostPosted: Sat Feb 20, 2010 6:59 pm    Post subject: Reply with quote

Definitely sounds like a digital problem. It could be anything from corrupted software(doubt that) to a leaky steering diode or a gate issue. Without some sort of a diagram it is rather difficult to pinpoint. It sounds like the data line is latched to a specific word or some sort of a A to D network tied to the analog pot is inoperable?
Back to top
View user's profile Send private message
sisbrains



Joined: 14 Feb 2010
Posts: 15

PostPosted: Sat Feb 20, 2010 10:46 pm    Post subject: Reply with quote

Thanks for your reply vtech, I have given up and put it all back together.

When I turn on the XBoard, it always starts with its output set to MIDI channel 2, so I have to change it manually to MIDI channel 1. When I start writing a song and try to output on MIDI channel 2 (or any other channel apart from 1), nothing is received by my sequencer, even though it has just been receiving on MIDI channel 1. I use Proteus X and that shows me MIDI activity on each track, so I can clearly see that it is outputting on channel 1, but not on any other channel. Perhaps it's a major 'something' that's broken down in the logic circuits.
Back to top
View user's profile Send private message
sisbrains



Joined: 14 Feb 2010
Posts: 15

PostPosted: Sat Feb 27, 2010 12:47 am    Post subject: Reply with quote

Problem solved!
After nearly buying another XBoard on Ebay for just under £100 (but thankfully I held back, because I thought I still might find the solution), I searched through the manual...

Page 40: To Select one of the X1 or X2 Functions:
1.Press the Edit button. The Edit LED illuminates.
2.Select X1 or X2.
3.Adjust the data slider or use the Octave Transpose buttons to view the
functions.
4.Press Enter to select the desired function.
5.Select the desired value using the data slider or the Octave Transpose buttons
(except with CAL).
6.Press Enter to confirm your selection. Press Home to cancel the operation.

Calibrate Sub-Menu (CAL)
When you select CAL and press Enter, you are taken to the CAL sub-menu, which contains calibration functions. To select a function, use the data slider to select a Calibration function, and press Enter. To cancel, press Home.
CCM
This feature enables you to calibrate any control on your Xboard, one at a time, optimizing your Xboards action for your playing technique. After you select the CCM function and press Enter, all LEDs on the Xboard turn off (except the display, which says adjust a control). This is Calibration Standby mode. What you do next depends on which control you want to calibrate.

To Calibrate a Controller Knob, Mod Wheel, or Data En
1.Sweep through all possible values without pressing harder eit
than you normally would. As you adjust, the display shows ra
ues, reverting to the name of the control you are adjusting.
2.Press Enter to store the calibration, or press Home to back ou
cess. You are returned to the Calibration Standby mode.
3.Press Enter to calibrate another control, or Home to finish.
To Calibrate the Pitch Wheel:
1.Sweep through all possible values without pressing harder in
tion than you normally would. As you adjust, the display sho
trol values, reverting to the word Pit (as in Pitch Wheel).
2.Let the Pitch Wheel spring back to its normal position in the c
3.Press the illuminated Snap Shot button. The Edit LED should
in Center). You can repeat this step as many times as you wa
4.Press Enter. You are returned to the Calibration Standby mod
5.Press Enter to calibrate another control, or Home to finish.



(Just in case anybody out there has the same problem, and doesn't want to trawl through the manual).

By the way, the "X2" key is one of the keys on the keyboard itself - the ones on the lower end of the keyboard have functions written above them.

I am so happy! I was just about to spend a fortune on another XBoard, and sell mine off for a fraction of its worth, as 'faulty', and now I've fixed it in two minutes!

I also solved the problem whereby it was defaulting to MIDI channel 1 on startup - I must have accidentally set up keyboard patch no.1 with it transmitting on MIDI channel 2, and hence every time I turned on the keyboard, I had to adjust the MIDI channel output back to 1. I just followed page 25 of the manual and resaved the patch, this time with it outputting on MIDI channel 1.

So everything is fixed, my XBoard is working beautifully, and it works a treat with Proteus X - all 16 main parameters are already mapped to the control knobs, it's wonderful!!!

Thank you all for your help, if I only I had RTFM! (Read the f***ing manual!)
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic    Electronic equipment repair and service manual search discussion Forum Index -> Equipment Repairs All times are GMT
Goto page Previous  1, 2, 3  Next
Page 2 of 3

 
Jump to:  
You can post new topics in this forum
You can reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum


 - Service Manuals Free Download - Prikachi - Service Diagrams

Free TV Schematics Download - HARDW.net - Pinout Master - Jabse Search - Jabse.InK  - Pulsator

Connector Pinout Forum -  - SnimkiOt.com - DNS - Whois  - Poblizo.com :