Most of them have woodscrews ran up thru the bottom of the TV to hold it to the wood. Where is it mounted I may be able to help you out a little better and if you can post a picture.
It's mounted in the front at top. I've got the trim off and some screws on the side off but it seems like it has to lift up off of a lip in front bottom and slide up. The trouble is it won't lift up enough to go over the lip. I'll get some pictures and post them. Thanks
check for wood screws up underneath the cabinet it is in. alot of times they are screwed up thru the bottom of tv to keep it from moving. If it lifts off bottom of cabinet it may have some straps on the back side somewhere. I worked as a tech in a RV dealership for awhile so anyway I can help I will. Once you post some pictures I can also get a better Idea.
Is it loose in the frame itself. If it is you may need to pull that trim off. Just be carefull and it will go back on fine. Also it almost looks like it is in a cradle. I may be seeing stuff in the picture though. Is there clearance at the top.
Can the cradel it looks like its in be loosened from the side and lowered at all. If not then looks like you are going to need to pull the trim ring around front of cabinet