iPad not charging

Hi, having a problem with iPad model A1475 and not charging. I've check cable & charger are all good and left it charging for hours. I've cleaned lightning socket but same problem. When I try to switch ipad on a get a battery icon with a single red flashing bar in the middle of the screen and the lightning connector icon at the bottom and that's it! I've tried holding power/home buttons to get it working but no luck. Plugged into computer running iTunes and nothing! Any ideas? If it's broken, is it repairable do you think and at what sort of cost?