Acer Aspire laptop power problems

Hi,
I'm having major trouble with my laptop (an Acer Aspire 3660) which is about 2 years old now. I don't know if there is a problem with the internal power socket or something else, but sometimes when it is plugged it just won't run off the mains or charge the battery. Sometimes I can get it to charge up, seemingly by rotating the power cord cable but at other times it will randomly go to battery even though absolutely nothing has moved, and sometimes it will go to battery power with the slightest little nudge. I don't think this could be related to the battery as the battery seems to work fine (although it does drain quickly I guess it's pretty old in laptop terms). Has anyone else had this problem or have any suggestions? I bought a new power cable (completely new including power pack and the plug end) but the problem still happens.
Thanks very much to anyone who can help!
Willow

 

Problay dc jack if don,nt mind play with take apart

does the connection where cord plug in look lose when can move the center pin?

 

The connection doesn't look loose but when I have the lead plugged in, you can move it around a little bit from side to side, but I don't think this is different from before the problem. The end of the lead looks fine and the inside of the connection on the laptop looks fine also.

 

remove battery does power light go off and on when you move it the little

It old model i say just carefull pull apart check solder jioint

 

It looks pretty complicated to pull apart. I haven't been able to turn it on for the last 7 days at all. No matter what I do or how much I carefully adjust the power cord it will not connect to the power supply. Any other suggestions?