Hello, did you manage to repair it, I have a Roland rs-70 that is identical on board to the juno D, only with foppy and USB, this keyboard turns on the panel lights, and they flash, and the LCD does not show anything, I can't find the problem, Everything seems fine, and I am not very skilled in electronics, I already replaced all the MB capacitors, all the SMD capacitors of IC 18 and IC7, changed Q17, found Q19 bad and Q16, the same DBeam LED is burned out, and I don't know how to measure IC6 on the panel. I don't know if the keyboard sounds, can you help me with what you did with the keyboard at the end?

Mod: link to old thread. @Yami
https://forum.allaboutcircuits.com/...zer-gets-stuck-at-startup.163830/post-1501075

 

checking c70 when turning on and testing continuity with the diode scale it goes short, but when injecting voltage into C105 and C43 nothing happens, the C70 LSCAN3 does not have any voltage, hence they are present practically in all the places where I measure voltages, LCDPWM only gives 1.3v out of 5 that it should have, DBSIG is not there, I tested the LCD with direct voltage of 5v on its legs and it did not give any function. Otherwise ic41 lost its legs due to corrosion and I will have to change it but when compared to the juno D it is not a component that is crucial for it to start, it only controls the Floppy and the USB, which are not working either, the main power supply gives 8.33v and 4.95v

 

Here is the Service manual, for comparate Whit Juno D is almost the same

 

Hi guys, here is a video of tha what I have reached in this fixing, please someone could help me please
https://youtube.com/shorts/LLV6T8Vlb54?feature=share