I have a HP Pavilion DV4000 that is not powering on. The A/C connection seems to be loose and not fitting in tightly like it usually does. I also do not see the blue light where the connection goes into the computer. Would this be caused by the charging port not connecting with the Power supply on the motherboard. Could the motherboard have failed? What should I do to find out what the issue is and how to go about fixing this problem. Thanks for any suggestions.