Hi there, how's it going?
I don't know if you are still waiting on an answer on how to fix the "dead space" on top, bottom or sides of the screen, but here's what you need to do in case you are still wondering or maybe for someone else who's having the same issue.
Once you take the DMD board off the tv and install it back on, you have to re-align it to the center of the projection housing.
This is how you do it:
You can do this procedure by yourself but there will be a lot of going front and back to check on the screen so if you can get someone to help you while you do this, that will save you a lot of time!
Ok, on the DMD board housing you see there are two screw holes on the left, one screw hole on the right and the four spring loaded screws. Once you have placed the board back on the housing, go ahead and screw in the seven screws but don't tighten them all the way. Make sure they're loose enough so you can move the board up and down and from side to side but not too loose that the screws can't hold the board in position.
Once you've done this and made sure you connected all the wires back on, turn your tv on with access to your service menu and there will be a screen calibration option somewhere in there which consists of a grid that will be visible on the screen. (I don't have the original remote to my tv so I can't access the service menu and therefore I can't exactly say where this option is but I'm sure if you look around you will find it) Once you've found this option you will want to center that grid to the screen and you do that by moving the DMD board OPPOSITE to the side you want to go to. If you want the projection to go to the left of the screen, move the board to the right, if you want it to go down, move the board up.
If you have someone to help you, just have them look at the grid in the screen and let you know which direction to move the image to.
If you don't have help, just adjust little by little and check the grid as often as you need to until you're satisfied with the image centered in your screen.
Once you're happy with the result, go ahead and tighten the three screws on the sides first making sure you don't move the DMD board out of alignment and then the four spring loaded screws and that's it...you're done!
Hope it helps and good luck with your tv.
You all have a great day !!