Del Inspiron 5150

My trusty and yet older Inspiron 5150 is acting weird. at times when I hit the power button the power light will go on for a few seconds and then nothing happens. Also sometimes when I do that the power supply fan is still running.

Tonight I was able to get the laptop to boot but when I moved the machine it just shut down. I think I have a loose power supply if that is possible.

The question is, could it be anything else, and is it worth replacing the supply in a 5 year old laptop

(Yes I know I probably misspelled something up there don’t need to know about it. Thank you)