Korg Poly-800 MK1 Works with batteries but not the power supply

Hey all, so a few months ago i acquired a Korg Poly 800 in non working condition for $30. I brought her home and after a few days of sitting on the workbench i finally made it to the store and got some C batteries and …viola! It was back to life. Loaded up the factory presets, ordered some missing slider caps from here and it was sounding and looking great !

Still though, i would like to avoid having to buy C batteries for it in the future for it, one round to the hardware store and i spent almost as much on batteries as i paid for the bloody thing ! I’ve been trying to fix it but i’ve hit a brick wall. I’ve read in another thread that the first couple of diodes and capacitors can get fried by using the wrong power supply, but the ones in question (D2) seems to have been recently replaced and i’m getting continuity through that entire part of the circuit. Any tips for troubleshooting? Any help or advice is appreciated !

I’m using a standard Korg 9V power supply, and have tried several 9V power supplies that should all work with it.

Thread in question :

from the schematic:

service manual: