Inspiron 5100 auto shutdown without warning

Inspiron simply shuts down when I start moving it around.

 

Turned off all power options including "when i close the lid", it is still acting up. Here is what I know so far

1) I don't think it is a overheating issue, I set the computer on a table, turned the fan on high, temp came down to 33c, I touched the lid and it shut down. Did same thing second time, started picking it up from bottom of computer and it shut down. As I said above, according to the temp program my computer is not getting much above 40c

2) Usually when it shuts down, I have to unplug the ac cord then plug it back in, than I can turn the computer on. If I don't do that it won't turn on.

3) does it on ac or battery

4) Does it while just idle in windows or running programs

5) Shutdown gives no warning, it goes from windows to black screen instantly

any suggestions?