Jd-800 No Sound

Hello I found a JD-800 with no sound. Any tips on what it could be or similar synth that has an issue like this?

Thank you

I probably won’t be able to help much but I find it’s a good idea to test whether the keyboard will make sounds when you hook up an external keyboard to it via MIDI. I also like to test it backwards. Hook up the keyboard in question to a known working external sound device via MIDI and see if the keyboard will transmit a MIDI signal to the external device. That will help with the troubleshooting and you should be able to determine what to check next.