From cheater00 .
Sent Fri, May 10th 2013, 14:43
sounds like a cold solder. are you a tech? try disconnecting the power supply and connect a soupy linear bench power supply. try to trigger the bug while observing the voltage rails on the scope with the original psu. On Fri, May 10, 2013 at 2:11 PM, System 100 <firstname.lastname@example.org> wrote: > Hi all ! > > I bought a second hand Voyager a while ago and just found it has a severe > issue... Once I power it on, after a few minutes the overall pitch can > change dramatically and intermittently for a fraction of a moment and than > return to normal. I can happen after a few minutes or after half an hours > after powering it, and it can come and go spontaneously. It can be heard > when using MIDI or the keyboard, and it happens also when the pitch wheel is > disabled. > > Please take a look at this video, of an RME acting exactly the same as mine: > > http://www.youtube.com/watch?v=Ew5DQXc-xko > > The guy there says it was sent to moog for repair a few times and it still > acts the same... Can anyone think of any idea what causes it ? > > The voltages are stable and when the pitch changes no change in the main > voltages is observed. All connectors and ICs are tightened in place... All > functions performs well and all pots are in good contact... > > The only irregular thing I notices was that the 4 transistors on the small > powersupply board (not the main PS board) are very (very) hot. No heatsink > was built around them, just thought one of them might have gone bad but > again, all voltages are pretty accurate. > > Will appreciate any help.