Emax

yes a cold solder joint will do it as they are done in banks if one goes the whole octave will go

if it was just one key then i would of said dirt on the spring contact or the spring has snpped or fallen ot which also does happen
  ----- Original Message ----- 
  From: jaumemod 
  To: emax@yahoogroups.com 
  Sent: Monday, July 09, 2012 11:14 PM
  Subject: [emax] Re: Five top keys fault


    
  The maneuver I performed for it working again was to raise the contact spring with a nylon stick while pressing one of five keys on the MIDI master keyboard. Then everything was returning to work.

  This must create a bridge between contacts or something similar

  Ouuuuk! For the moment I traced the contact ways to contact key and I find a bad solder point....perhaps it's the cause which when I turn upright sampler all faults again.

  Tomorrow I ll put a bit solder....I'll tell you something...

  THX a lot

  --- In emax@yahoogroups.com, "jammie" <jammie.emma@...> wrote:
  >
  > i agree i recon its a diode or the return circuit to the scanner cpu
  > 
  > the scanner cpu gets pulse signals from when a key is pressed0volts to 5volts to zero volts like a half square wave cycle
  > 
  > he says he is getting voltage across the diode 5v when key is pressed
  > 
  > so to me the keys is making a circuit as tested but that siganl is not getting back to the cpu scanner
  > 
  > now its either the wire for that octave is damaged or there is a broken track 
  > 
  > he needs to trace the tracks from that octave and see if he is getting continuity to the header cable if he is then its at the mother board end 
  > 
  > as the scanner cpu is not recieving the trigger pulses for that octave
  > ----- Original Message ----- 
  > From: emax_dx5 
  > To: emax@yahoogroups.com 
  > Sent: Monday, July 09, 2012 6:09 PM
  > Subject: [emax] Re: Five top keys fault
  > 
  > 
  > 
  > 
  > Yeah I don't discard it at all, but three 1125's I had to deal with were completely dead when failing. Talking about a failing octave (just that) I would go for traces or diodes (appart from all suggested above). Those keyb pcbs are prone to crack traces . 
  > 
  > --- In emax@yahoogroups.com, "jammie" <jammie.emma@> wrote:
  > >
  > > actually i can be the scanner chip iv had it when you can play notes on kewyboard but when pressing buttons its arratic and jumps allover the place
  > > ----- Original Message ----- 
  > > From: emax_dx5 
  > > To: emax@yahoogroups.com 
  > > Sent: Monday, July 09, 2012 2:59 PM
  > > Subject: [emax] Re: Five top keys fault
  > > 
  > > 
  > > 
  > > I won't go for the MPU Scanner (IM386). When it fails, no button or key usually work.
  > > 
  > > You said you sent midi to the Emax and it made sound. Did you check the MIDI OUT commands the emax is sending? you can do it both with a Midi analyzer on your computer or using the function MIDI Scope. Check if it sends Key ON and OFF commands or not. If any of those cases:
  > > 
  > > Go to the keyboard Printed Circuit Board. ONce you already checked diodes, Check continuity on the traces involved with those keys (a multimeter will do the job). If a common ground trace is open, this fault uses to happen.
  > > 
  > > hope it helps.
  > > 
  > > Best.
  > > Jose
  > > 
  > > 
  > > 
  > > 
  > > 
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  > >
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