I just bought Roland RS 9. All works except ensemble toggle switch not working. Everytime turn on, no sound at all…Both on organ or string. I checked on circuit board of control panel ( not tuts board), I found 4 IC sockets are empty. no IC plug in. it seems IC310(MN3101). I’m not sure this IC are empty from default factory (MK 1 version) or someone took it off. Does any one check if the socket IC310 empty or not? Or anyone have a Photo of circuit board of control panel?
First: This is assumingly an RS-09, not an RS-9 (the latter is a digital 64 voice synth - not a string machine)-
These sockets must contain the BBDs (Reticon SAD512D). Not the 3101!
Someone ripped them off.
Unfortunately these Reticon chips are extremely rare and as NOS they are quite expensive. (I found only offers $75 per piece)
To replace them with the MN300x is not a the easiest job (develop an addon pcb that contains the MN300x a MN3101 and some preparation for the clock)