It's a little tricky to make the code work on the remote: you need to power the TV off, hold the remote up to the bottom-right corner of the TV (where the nub that receives the IR signal of the remote is), then press one at a time Mute-1-8-2-Power on the basic remote. It sometimes takes a few tries before it works. Here's a video of it being done on another Samsung TV, albeit with a different remote code.

If you have difficulty to go in the service menu, you might try to do a power cycle, by unplugging the power cable of the TV or by pressing those remote buttons at the same time (Info + Settings + Mute + Power), and try again.