Hi. I have an iphone 6S and recently it wouldnt charge. It had a new battery and worked fine. But what ive fond out that it does, that if the battery have life in it, it will charge fine. When the battery runs down flat, it wont charge. Basically then, it will charge fine when its got charge left in it, but if its left to run completely flat, it wont charge then. Could it be the charging IC and is it repairable?. Any help and advice would be gratefully received. Many thanks, Gary.