I had the same problem. This is how I fixed it:
1- Lay the MM6 upside down, remove the screws, open the back panel.
2- On your right side (the Volume PC board section), you will see component stand up (2 of them had 3 legs each, one of them is had more than 3 legs don't remember exactly) but 3 of them all had metal finish on their back. There are look like Power Transistor ( I do not have a schematic to be sure) but when these part get warm or hot (volume is only decrease when MM6 had been Turn-On for awhile), caused the volume to decreased.
3-Go to Radio Shack or other electronic stores, buy 3 HEAT SHRINK or you can make them your self (find- google to see what it look like, marterial...etc);
4- Use small screws and nuts, install these HEAT SHRINK into these 3 component then they will help these 3 components to stay cool all the time, therefore it will fixed the Volume decrease problem.
5- Yamaha should put HEAT SHRINK into these part when they designed.
I have had this problem too. Often just turning it off and restarting the keyboard fixes the problem, however a year ago this easy fix did not work and so I opened the machine up. I had to remove a few screws and turn the circuit board over. Sure enough, near one of the output jacks there was a solder joint that looked darker than all the other. I uses a solder gun to reheat the solder joint and all worked well again for another year, at which time I had to do it again. I wonder if others have been having this problem.
I ran into the same problem (losing volume during shows, and having to restart the keyboard during live songs, ugh!) and this solution does work. I remove the screws holding the back half of the botttom of the keyboard, then unscrewed the four screws around the sound output and power adapter ports, then remove the screws around the board holding the ports, carefully remove the center ribbon and flip over the circuit board. Using a soldering gun, heat up the top solder spots underneath each port that is causing you problems, then put it all back together. Success!!
how do you "restart" the board?
×
935 views
Usually answered in minutes!
×