Roland RS-202 advice for a newbie

Hi everyone, extremely green user here! I have recently become unemployed due to health issues and have so much time on my hands. I’d love to learn a bit about keyboard repairs (Synth Wizards is party to blame for this, such a great show!). I’ve fixed a few vintage electronics in the past but this is a clear step up for me. I have bought a very cheap slightly beat up Roland RS – 202 which powers on but does not produce any sound. I am chasing some advice on where to begin diagnosing this issue, and if it is actually worth attempting to fix? Any tips would be greatly appreciated.

Cheers from Aus,

Synthchaser on youtube has many good synth troubleshooting videos.

First thing:
Don’t switch the device on, as long as you aren’t sure, that the internal supply voltages are correct

Check whether the fuse is intact.

Then: Get the service manual:

Orientate your self inside the synth

Then disconnect all connections from the powersupply pcb to the other pcbs (keep in mind which wire comes from where) and measure the supply-voltage outputs.

If those are ok, then you may reconnect the connections and start searching in the audio circuits