Thanks for the suggestion, I've tried grommets, glueing graphite disks, and replacing the contacts themselves, I'm not sure I want to keep playing with this issue over and over again. I have to try to find an adaptable keybed to put an end to this. wonder if any of the older casio's or other older t...

Yes, I've replaced a few last year and they are now failing again. No amount of cleaning the contacts seems to help. So I want to replace the keyboard and be done with it once and for all. I've also tried the grommet trick inserted in the keys but same issue due to the failing rubber contacts any id...

Hi all, maybe someone can help me out here. I've replaced the rubber contacts on the keybed of my poly-61 numerous times and they still fail after awhile, not to mention the price of them has skyrocketed from a few existing sources. Just wondering, if another keyboard (keybed) can be adapted to work...

OK THIS SYNTH IS FINALLY and OFFICIALLY FIXED!! After I qualified all ribbon cables. resoldered the connectors, checked all transistors, I moved away from the Switch board and concentrated on the main board there I started to check all signals from IC13 to the connectors, well all were good except 1...

Hi Yekuku, good to hear from you. So I spent 4hrs troubleshooting the Switch B board and found nothing.. all transistors are good, traces, ribbon cables all test good continuity and ICs were replaced twice now. So I concentrated on IC1 & IC4 or the LED portion only since the tact switches all work. ...

Hi the display itself has no adjustment, you'll have to go on the circuit board and adjust VR1
look at the attached schematic. Its a small potentiometer that you can adjust with a precision (or small) screwdriver. Hope it helps

Yekuku, thanks I already checked all those and PA10 & PA11 lead me to the main processor but nothing on those lines/bus to test. During the Switch & LED test, the LEDs do not come ON, only the tact switch test is acknowledged on the LCD display. Strangely the LEDs initially turn on on boot up.. I do...

Hi Yekuku, yes I qualified all transistors, GND lines, and power lines checked the caps as well all done with component tester and continuity checks with a voltmeter. the two transistors Q7,Q8 pertaining to the Beat A & Beat B on the switch B board are good, I'm not sure if they are related to the s...

Here's a short video of the LED issue. I'm searching the Beat A & Beat B signals coming from the main board schematic to see if there is some circuitry with some related caps that could be the issue. hope this video link works out.. :D https://drive.google.com/file/d/1wloxvNKI4bZELyM3o7tRQzz5pc6H6U4...

Hi, I'm not pretending I know the JV-880, but I had some distortion / noise issues with my XP-80 and really only got intimate with it after reading the manual and trying to figure out the signal path from the schematics and the help of yekuku on here to reason out my suspicions. I would run the test...

Thought I'd update this and say that by replacing the DAC again solved my distortion issue. the synth sounds great now and all tact switches are good. Although I seem to have another issue with the LEDs staying on. Upon boot up, the LEDs come on, when it goes into normal mode, LEDs like rhythm, sequ...

OK, I will double and triple check those lines and signals on them and look at any conspicuous electrolytic in the path, I just hope I didn't get a bad DAC, but nothing is impossible. thank you again

No worries, thanks for looking into this , I appreciate it

Well, unfortunately still no go. Took almost 1.5 months for my replacement IC's to arrive. So far, I replaced IC39, 40 & 42 and still no Sine wave. IC39 DAC voltage outputs are similar to IC41 outputs.. just no sine wave only SQ wave present at IC43 and down the line obviously. I'm still not sure wh...

Ciao Nico, stai bene? No you cannot turn on/off those voice led's, they are triggered by the CEM filter chips, try swapping the voice chips around if you are getting less than 6 voices to test for the bad CEM. but if its only a few keys, then the obvious would be to check the contacts below the keys...