Ok, I really appreciate you clarifying that for me.
Let's start gathering information together --
Main board. It controls practically EVERYTHING. Literally. It controls your tuner, your inputs, your menu, your volume, channel and even power control buttons on the TV and the remote.
Logically, if you are stuck on D1, that's Digital channel 1. If you have lost power to the TV set, it can sit there on D1 until you access the MENU, go to the PLUG and PLAY setting and program the TV again.
But since you can't even access the TV menu, we pretty much know that the TV's micro is partially dead.
I try to use the Menu button on the remote and the TV set to see if I can get the MENU to respond, but when both don't work, we have to replace the TV's main board.
Now there's some other things I do before ordering any board for a samsung.
First, Samsung has made ONE MODEL using 1 to 4 different Main boards throughout the manufacturing lifetime of that model. Sometimes it's only 1 board, other times it can have more.
That's why I actually LOOK at the board. Some have a BARCODED sticker on it, others have just a small white sticker with a BN number on it. THAT'S the number I trust the MOST!
Can you remove your TV's back cover (remove the screws holding any of your input connections to the back cover, and around the outer edge, and in the center of the Back cover) and take a look for that barcode sticker and get that BN number to me?