ipad 4. generation (2012) can not be restored/updated/properly started

Since yesterday it is not possible to start my 2012 ipad. It does not show in iTunes as device, it does not start properly. It shows the apple logo, shows recovery mode logo (itunes plus cable symbol) I tired the recover and update recommendations shown on apple support pages without success. The ipad is obviously connected and during attemps to recover, the serial number is read and shown on the recovery screen. Software update is downloaded and the system tries to transfar new software to my ipad, even the horizontal update bar under the apple loge appears, but then action stops with error (9). What should I do. Could it be a battery problem (although the logos are shown, i.e. there is power left on the ipad).