You may want to subscribe to PolySix@yahoogroups.com (which - as you might guess - is a dedicated Polysix users and repair group). In general I tend to no longer bother with repairing the battery damage (unless it's really minor) and instead install a "clone" KLM-376A board.
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Re: [vintagesynthrepair] Korg Polysix
2013-12-03 by Malte Rogacki