So like so many other people: My glass started sliding down on my Samsung PN50A650 plasma tv I purchased nearly 5 year ago (I think it was 2008).
After doing some reading and trying to round up a solution I came up with no detailed answer. So I figured I would tackle it over the weekend and take pictures along with doing a little write up on what I did to fix it. In no way does this mean it's the "right" way but honestly it was a piss poor design by Samsung and they won't take ownership of the problem. I think they realize it's not worth the hassle since it could very well happen again.
On to the repair.
For starters, it takes two people to fix the tv. I'm sure you could do it solo but seriously, grab a buddy. Secondly, the bezel comes off (unlike what other people claimed). Mine came off after removing the 10 phillip head screws.
The picture below shows double sided (white) tape on the TV. All the double sided tape does is holds the bezel flush to the metal trim pieces.
The bezel has pieces the stick out which slide into the slots of the metal trim (surrounding the glass). These "tabs" actually hold the glass in place. There are soft cushions on each metal trim piece which the glass sits on.
Now you know how it was designed, here is what happens. The TV gets hot, the double sided tape gets old and the bezel starts to loose it's grip with the tape. The bezel will then pull away from the metal trim pieces which also pull the tabs out from the slots. Now the glass starts to slide. This blocks the sensors and causes a gap above the tv.
Below you can see where the glass slid down. This is the gap you see.
There is two remedies I put in place to help "fix" the issue and eliminate it from happening again. First I purchased some 3M "indoor/outdoor" double sided tape. It's super strong and has great bonding properties and will bond with just about anything. On top of that it comes in at almost the right length (maybe only 3" wasted). I did not cut it in half. I left it wide and applied in just like it came out of the box. I made sure that I pushed down on the tape to ensure a good bond with the metal trim piece.
Also, be sure to remove the previous double sided tape... don't be lazy.
The next part to help was using aluminum tape on the glass and attaching it to the metal trim on the top side. It's durable, it can resist the heat of the plasma, and it does not cause any issues what so ever (at least so far for me). You do not see the tape when the bezel is back in place (obviously).
Once I installed the tape and made sure it was a good bond, I double checked the double sided tape and then we lowered the bezel back into place. With a few good firm presses on the lower bezel to make sure the double sides tape bonded to the bezel we put the tv back upright and put the screws back in place.
The tv works great and I expect plenty of life to remain out of the tv. It's wall mounted and there has been zero issues since the fix (fingers crossed). Samsung didn't want anything to do with me and the repair which doesn't surprise me for the age of this TV. They pulled the "it's normal wear and tear".... which is so bogus.
I hope this helps others out there who might run across this issues. It's seriously no big deal to fix. Just be patient, take your time and think about what you are doing. The hardest part was making sure everything went back together smoothly and in the right position. Personally I wasn't a big fan of laying my plasma on it's back, but it had to be done.