you can add a clear adhesive not to much, just enough to get it to stick and it will hold them bonded to it, you can pick up a tube of clear adhesive for around 2$ at walmart, home depot, ect, sorry for the late reply. just saw your email. if you have any questions just ask. i have done 100s of phones all kinds. do not listen to people who tell you to put super glue in your phone, not a good idea, if you ever have to replace or remove those parts again have fun:) But clear adheshive will come off easy with a little issolated heat, but give a strong bond unless you are intentionally heating it up. good luck.
your power connection on the motherboard could have come off or loose and needs to be soldered back on. pull your mobo out and pull up a schematic of what it should look like like, then look for anything different, or missing. find the part solder it on. You should be good to go:) Update: its usually a little gold plated prong by the power button there are two of them there, top left of motherboard. Hope it helps...