As I have this problem plus following guideline information on many sights still Lenovo 2 tab was completely dead having bought it mid 2015 .It is in the repair stores due back within next few days .I can report back here the electrical engineer report might be of some help to you people .I have a monthly general domestic repair and support insurance I took out when purchasing Lenovo I'm glad I did as it does cover this device for damage no matter how caused plus eccessaries if unrepairable I get a new one or voucher to redeem .Will report back soon hope I can guide you what might be the issue .My gut feeling is dead battery's or jack point damage I think that's what you call it, or gateway charging unit .