First make sure that an antenna is connected the coaxial input on the TV and the input is set to TV. There is an Input button on the top of the TV and on the original remote. On the remote, the Input button is below and slightly to the right of the 0 button. On the top of the TV, the Input button is the one closest to the Power button. You can toggle through the Inputs by pressing the Input button several times or use the up/down arrows and then press the Input button to select the input. (TV should be the top item in the list.)
Next press the Menu button on the remote, above and to the right of the arrow keys. (There is no Menu button on the TV.) Use the left/right arrows to navigate to Setup. Next use the up/down arrows to select CH setup. Press Enter. If you've set a PIN, you'll need to enter it. Use the up/down arrows to select the line Air/Cable, if you need to change the source of your signal. Press Enter. Use the left/right arrows to select your source. Press Enter to save the setting. Press Menu to exit. Return to this CH setup menu and use the up/down arrows to select CH Search and press Enter. If you are using an OTA antenna, use the left/right arrows to select Start and press Enter. Wait for the search to be completed. For cable sources, you'd need to select from Analog Search Start or Digital and Analog Search Start. Press Cancel and then Enter to exit the search.
Crutchfield has the manual for the LC-32D62U available from the product page under the Details tab: http://www.crutchfield.com/S-mhRC3OB2Fi4/p_284LC32D62/Sharp-LC-32D62U.html
. The direct link to the manual is http://d2stobyut4u5rx.cloudfront.net/ImageBank/v20080124174400/Manuals/284/284LC32D62.PDF
. The Input button use is available on page 30 of the manual. The channel search steps are shown on page 23.
I hope this helps. Please note, if you have an replacement universal remote, you may need to try multiple codes for Sharp TVs to get the Menu button to work. If your replacement remote doesn't have a Menu button or none of the codes work, then you'll need a different remote.