This synth is not working. Needs someone skilled in electronics repair to get this working again. The problem is the PSU. The M3 is famous for having a faulty PSU and unfortunately, a replacement is very difficult to find. However, if you know electronics, the PSU is actually pretty simple to rebuild, but it’s above my skill level, so I’d rather someone else up to the task take it off my hands. Priced appropriately for the right buyer to fix and turnaround for a handsome profit.
eBay