@kenmo yes it could be your charging circuit but start with the common component and that would be the battery. Replace that first then reevaluate. there are not a whole lot of schematics etc. around so you really would need to do plenty of research if it is your charging circuitry. Of course, when you replace the battery, double check all the boards and see if there are any obvious damaged components etc. You can always post a couple of images of what you see with your question. That way we can see what you see. Use this guide [guide|21499] for that and this guide [guide|98424] for the battery repair.