Just got a fairly new Sylvania lc32ossx from a friend, however, the remote was misplaced during a move and the owners manual is also. With the buttons on the tv I can pretty much do all the set ups except changing screen size of picture. The picture only sits in the center of the tv. I want it to be on widescreen or to take take up entire tv screen but cannot find settings for this manually. Can this be done only with the remote?

SOURCE: Need 3-digit TV remote code--Sylvania 15" LCD HDTV

many of the dish remotes have a "scan" option. This is what the installers use. You'll ned to read the manual. Its a one page explanation.

SOURCE: lost manual for new sylvania lc420ss8

http://www.sylvaniaconsumerelectronics.com/pdf/manual/LC420SS8.pdf

nice TV . heres the manual.

SOURCE: cant program direct tv remote with my new sylvania lc320slx

The remote is only programmed with only so many codes. Sadly, It doesn't hold all code for every TV made.
But you can try making the remote search every code stored inside to see if one of them will work.
Here are the instructions form the DIRECTV web site:

You may still find a setup code that works for your device by stepping through the library codes in your remote. The following instructions will help you do this.

StepNSet

• Set the "Mode Switch" to the desired mode such as TV for a Television.
• Press and hold the "Mute" button and the "Select" button until the visible LED blinks twice.
• Enter the code "991" followed by the "device number"
  1. for Televisions
  2. for "AUX 1" devices - VCRs or DVDs
  3. for "AUX 2" devices - Audio
• You can step through the setup codes for this mode by pressing the "Channel Up" key to go forward through the codes or pressing the "Channel Down" key to go back to the previous codes.
• You can try out each code by pressing one or more function keys such as power, volume or digit keys.
• When you've found the setup code that works for your device, press the "Select" key.

SOURCE: New TV 9 mos old, Won't stay on after power up? Remote or manual turn on, set keeps turning off after 1-2 second green on and brief screen flash.

I would try leaving the TV unplugged for 30mins so the TV can reset itself.
If that doesn't work, your TV should still be under warranty. I know 95% of come with a 1 year warranty.
The most common problem with Sylvania TVs made by FUNAI, the Backlight Inverter board fails to early in life. ( That's the part that powers the screen)
The Tv can't power up the screen and it turns off automatically. Basically called "Protection Mode" so it protects the other parts inside the TV.

SOURCE: remote code for att uverse to sylvania lc320slx lcd tv

My solution might be a little off because I called Comcast for the answer but it seems that the problem is that the code doesn't exist.

I called Comcast and they had no clue. But I called Sylvania and their reps were FABULOUS!!! Turns out, the TV makers send the cable companies the frequencies for each TV then the cable companies send them to a 3rd party to get the codes written.

This model of TV is new and there is no code written. The rep suggested that we countinue to check back on the Comcast website regularly to see if the code is posted. She said that the sales reps tend to get the info last.

The Sylvania rep anticipates a new code written soon because this is such a prevelant problem.