I love this thing so far. It’s exactly what I needed to take my music project to the next level. Everything is going great and then after a while of playing, and very intermittently, the volume across all voices will duck down. The volume dips by different amounts but never really to zero. Sometimes it’ll duck out in little bursts and sometimes its a one shot and then stays low for 10-15 seconds. Also occasionally a single note will get stuck and ring indefinitely or until I do a keyboard reset, but this could be related to bad sysex when transferring new patches. I’m not sure if the two problems are related at all.
So, here’s what I know about this unit so far:
metal case version with ESQ-1 120v transformer w/ *5601 rev 1 PSU
os 3.53 (hidden waveforms)
has sequence expander cartridge
battery replaced (reading strong enough 2.9v)
it appears that the power supply has had a fairly amateur recap job done but I touched up the soldering and checked connections and it seems ok enough to check levels
5v digital (pins 10 and 11) showing +4.83v under load
+V unreg +10.9v
+12 Analog +11.8v
-12 Analog -12v
filters all between 140 and 146
I’ve reseated all connectors, removed the display and keypad board, cleaned/checked all sliders and buttons. The problem occurs through both output jacks.
System reset has been done a few times. Established a sysex connection and checked midi settings. I’m pretty sure the main board is a used replacement because it has $98 written on the lower left corner. I have yet to start pulling chips and reseating them because I want to check in with those more experienced than I am to make sure I get the correct procedure down. I’m fairly convinced the problem is somewhere on the main board, possibly a cold solder joint, but where to start…
I greatly appreciate anyone with some experience chiming in with tips or words of encouragement. Help me save this gem.