Recently, I purchased a second-hand OP-1 synthesizer. Upon connecting it to USB power or attempting to turn it on, I encountered a cracking noise from the device. However, the display remained blank whether I turned it on with or without the charger connected. After leaving the OP-1 on charge for three days, I attempted to turn it on while pressing the “COM” button. This time, the display showed the following message: “Rev 11964 (modified); 2011/09/16 20:16:39 188.8.131.52 HF-TAR44301”.
Could you please advise me on how to fix this issue? Any suggestions or solutions would be greatly appreciated.