So I decided to get a new HDD for my MacBook Pro 14" Mid 2012 and ordered a Seagate 1 TB SSHD with 8 GB NAND from Amazon a few days ago. Received it today, installed it myself and was able to install a new Mac OS X installation on it, but noticed that during the installation the charger light is off and that the Mac is not charging at all but using the battery instead. Tried to charger on another Mac and it was working fine, inserted it back into my Mac and it kept the green light for a few seconds and started dimming till it became almost unnoticeable except at low light conditions. The battery is completely drained now and I am not able to turn the Mac on again, so what are my options :/. Thanks all.