How do I determine what is the correct replacement motherboard for a Toshiba Satellite C665D-S5084 PSC16U-053030? My problem with the machine is that not enough voltage is getting through the motherboard to the battery to charge it. There is a second identical machine on site that I use to recharge the battery so I know that all other aspects of the machine work fine. I'm getting 19.5 VDC to the DC jack which I have already replaced thinking that was the most likely culprit. I don't know what else to do after that except to replace the motherboard.