Hi people, I'm by no means proficient in things electronic, but have previously have success repairing things by following the advice of people that do know things, and so I'm trying my luck again.
I dug out my old Roland JV30 keyboard from my high school band days, and wanted to hook it up. Unfortunately I used the wrong power-supply that didn't give the required 9V 1000mA but something a little more, the result was the display fluttering a bit for 20 seconds then a dead device. I now found the right power-supply but the keyboard still wont do anything, besides giving a faint hum in the earphones.
With my limited knowledge I assumed there would be a fuse that was blown or something similar, but taking apart the keyboard I cannot locate any fuse looking components, I can't see any obviously fried or burnt elements either- how do I proceed with error checking ?
I have taken some pictures of the circuit board where the power is attached and the schematics from the service manual:
The circuit board
![IMG_4844.jpg IMG_4844.jpg](https://www.electro-tech-online.com/attachments/img_4844-jpg.83576/)
Close up of the area where the power arrives
![IMG_4849.jpg IMG_4849.jpg](https://www.electro-tech-online.com/attachments/img_4849-jpg.83577/)
Element (I think its a zener diode) that I thought looked suspicious
![IMG_4851.jpg IMG_4851.jpg](https://www.electro-tech-online.com/attachments/img_4851-jpg.83578/)
Schematics
![mainboard.png mainboard.png](https://www.electro-tech-online.com/attachments/mainboard-png.83579/)
![mainboard3.jpg mainboard3.jpg](https://www.electro-tech-online.com/attachments/mainboard3-jpg.83580/)
Is there by chance anyone that can offer me some advice ?
With hope
Tom from Denmark
I dug out my old Roland JV30 keyboard from my high school band days, and wanted to hook it up. Unfortunately I used the wrong power-supply that didn't give the required 9V 1000mA but something a little more, the result was the display fluttering a bit for 20 seconds then a dead device. I now found the right power-supply but the keyboard still wont do anything, besides giving a faint hum in the earphones.
With my limited knowledge I assumed there would be a fuse that was blown or something similar, but taking apart the keyboard I cannot locate any fuse looking components, I can't see any obviously fried or burnt elements either- how do I proceed with error checking ?
I have taken some pictures of the circuit board where the power is attached and the schematics from the service manual:
The circuit board
Close up of the area where the power arrives
Element (I think its a zener diode) that I thought looked suspicious
Schematics
Is there by chance anyone that can offer me some advice ?
With hope
Tom from Denmark