My Juno 60 generates no white noise

Hi,I have a Roland Juno 60 that seems to not be able to generate noise from the DCO. All the other waves are sounding, no problem. Just wondering: Would that possibly require a full replacement of the DCO chip, or is the white noise generator on a discreet, replaceable chip of it’s own? And in Either case, do you guys have the necessary parts in stock?